bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomass allocation and phosphorus economics of rain-forest seedlings: effects of fertilization and radiation on soil specialists and soil generalists
Authors: Gleason Sean M. , Read Jennifer , Ares Adrian 
Published: February 2011

Abstract:Concurrent nutrient and radiation limitation in forests may engender trade-offs between P-use and radiation-use efficiency in tree species. To quantify these trade-offs, structural and physiological traits were examined among five rain-forest species subjected to four levels of fertilization and two levels of radiation in a glasshouse experiment. Schist specialists,Cryptocarya lividulaandCeratopetalum virchowii, occur only on P-poor schist soils, whereas soil generalists,Cryptocarya mackinnoniana,Franciscodendron laurifoliumandMyristica insipida, occur on both P-poor schist and P-rich basalt soils. Wild seedlings less than 20 cm tall and 1 y old were collected from field sites, treated with fungicide, sorted into treatments (48 plants per species), and grown for 11 mo. We hypothesized that soil specialists would possess mainly non-plastic traits conferring high P-use efficiency, whereas soil generalists would possess markedly plastic traits conferring high radiation capture and use, enabling them to outcompete specialists on P-rich soils. Only generalistC. mackinnonianaand specialistC. virchowiisupported these hypotheses.Cryptocarya mackinnonianahad more plastic root mass fraction, leaf area ratio, P uptake, and higher C assimilation thanC. virchowii, which resulted in greater relative growth rates in high P treatments, but lower P-use efficiency in low P treatments. In contrast, specialistC. lividulademonstrated similar trait plasticity asC. mackinnoniana, suggesting that plasticity in these traits may be poor indicators of fitness on P-poor soils.
Regional-scale heterogeneity in primate community structure at multiple undisturbed forest sites across south-eastern Peru
Authors: Palminteri Suzanne , Powell George V. N. , Peres Carlos A. 
Published: February 2011

Abstract:The forests of western Amazonia support high site-level biological diversity, yet regional community heterogeneity is poorly understood. Using data from line transect surveys at 37 forest sites in south-eastern Peru, we assessed whether local primate assemblages are heterogeneous at the scale of a major watershed. We examined patterns of richness, abundance and community structure as a function of forest type, hunting pressure, land-management regime and geographic location. The primate assemblage composition and structure varied spatially across this relatively small region of Amazonia (≈ 85 000 km2), resulting from large-scale species patchiness rather than species turnover. Primate species richness varied among sites by a factor of two, community similarity by a factor of four and aggregate biomass by a factor of 45. Several environmental variables exhibited influence on community heterogeneity, though none as much as geographic location. Unflooded forest sites had higher species richness than floodplain forests, although neither numerical primate abundance nor aggregate biomass varied with forest type. Non-hunted sites safeguarded higher abundance and biomass, particularly of large-bodied species, than hunted sites. Spatial differences among species assemblages of a relatively generalist taxon like primates in this largely undisturbed forest region imply that community heterogeneity may be even greater in more species-rich taxa, as well as in regions of greater forest habitat diversity.
Predictable timing of oestrus in the tropical bat Saccopteryx bilineata living in a Costa Rican rain forest
Authors: Greiner Sabine , Schwarzenberger Franz , Voigt Christian C. 
Published: February 2011

Abstract:Many tropical mammals reproduce seasonally, although the circum-equatorial climate is more stable and less seasonal than that of temperate zones. The mechanisms underlying seasonal reproduction in the tropics remain enigmatic. Female reproduction and its relation to environmental factors were investigated in the Neotropical bat species Saccopteryx bilineata. Colonies consist of year-round stable groups of several females that are defended each by an adult male. Females give birth to a single offspring each year and it is suggested that mating is restricted to November and December. In this study, it was asked whether females of a Costa Rican colony come into oestrus around the same time each year and whether oestrus times are synchronized. Oestrogen and progesterone metabolites were monitored from faeces between October and January in four years. Oestrus was identified in 32 females. In addition, climatic factors such as rainfall and temperature were monitored at the study site. Results indicate that (1) females exhibit monoestry, (2) oestrus dates cluster around the first half of December, (3) reproduction is strongly seasonal and highly predictable and (4) oestrus times are possibly influenced by long-term cues like photoperiod and short-term cues like sudden changes in rainfall and temperature.
Longitudinal and spatial distribution of GP60 subtypes in human cryptosporidiosis cases in Ireland
Authors: ZINTL A. , EZZATY-MIRASHEMI M. , CHALMERS R. M. , ELWIN K. , MULCAHY G. , LUCY F. E. , DE WAAL T. 
Published: February 2011

SUMMARYWithin Europe, Ireland has one of the highest reported infection rates with the diarrhoeal protozoan pathogen Cryptosporidium. In this study 249 Cryptosporidium parvum isolates collected from Irish patients between 2000 and 2009 were subtyped by sequence analysis of the GP60 locus. A subsample of 127 isolates was also typed at the MS1 and ML1 loci. GP60 subtype IIaA18G3R1 was the predominant subtype in every year and every season throughout the country. Over the 10-year period there was no evidence that host immunity to the predominant subtype caused a shift in its prevalence. Length frequency distributions of the GP60 TCA/TCG repeats compiled from published data, showed distinct patterns for countries with predominantly zoonotic or anthroponotic transmission cycles, respectively. Although considered to be mostly affected by zoonotic cryptosporidiosis, the GP60 fragment length of Irish C. parvum isolates mirrored that of countries with predominantly human-to-human transmission, indicating more complex routes of infection between livestock and humans. Due to their homogeneity, ML1 and MS1 were not considered useful loci for subtyping C. parvum strains in Ireland.
Shigellosis outbreak linked to canteen-food consumption in a public institution: a matched case-control study
Authors: GUTIÉRREZ GARITANO I. , NARANJO M. , FORIER A. , HENDRIKS R. , DE SCHRIJVER K. , BERTRAND S. , DIERICK K. , ROBESYN E. , QUOILIN S. 
Published: February 2011

SUMMARYOn 13 November 2009, the authorities of Flemish Brabant, Belgium, received an alert concerning a potential outbreak ofShigella sonneiat a public institution. A study was conducted to assess the extent, discover the source and to implement further measures. We performed a matched case-control study to test an association between shigellosis and canteen-food consumption. Water samples and food handlers' faecal samples were tested. The reference laboratory characterized the retrospectively collectedShigellaspecimens. We found 52 cases distributed over space (25/35 departments) and time (2 months). We found a matched odds ratio of 3·84 (95% confidence interval 1·02–14·44) for canteen-food consumption. A food handler had travelled to Morocco shortly before detection of the first laboratory-confirmed case. Water samples and food handlers' faecal samples tested negative forShigella. Confirmed cases presented PFGE profiles, highly similar to archived isolates from Morocco. Foodborne transmission associated with the canteen was strongly suspected.
An overview of the epidemic of highly pathogenic H5N1 avian influenza virus in Egypt: epidemiology and control challenges
Authors: ABDELWHAB E. M. , HAFEZ H. M. 
Published: February 2011

SUMMARYEmergence of the highly pathogenic avian influenza (HPAI) H5N1 virus in Egypt in mid-February 2006 caused significant losses for the poultry industry and constituted a potential threat to public health. Since late 2007, there has been increasing evidence that stable lineages of H5N1 viruses are being established in chickens and humans in Egypt. The virus has been detected in wild, feral and zoo birds and recently was found in donkeys and pigs. Most of the outbreaks in poultry and humans occurred in the highly populated Nile delta. The temporal pattern of the virus has changed since 2009 with outbreaks now occurring in the warmer months of the year. Challenges to control of endemic disease in Egypt are discussed. For the foreseeable future, unless a global collaboration exists, HPAI H5N1 virus in Egypt will continue to compromise the poultry industry, endanger public health and pose a serious pandemic threat.
Emplacement of magma at shallow depth: insights from field relationships at Allan Hills, south Victoria Land, East Antarctica
Authors: Airoldi Giulia , Muirhead James D. , White James D.L. , Rowland Julie 
Published: February 2011

AbstractAllan Hills nunatak, south Victoria Land, Antarctica, exposes an exceptional example of a shallow depth (< 500 m) intrusive complex formed during the evolution of the Ferrar large igneous province (LIP). Dyke distribution, geometries and relationships allow reconstruction of its history and mechanics of intrusion. Sills interconnect across host sedimentary layers, and a swarm of parallel inclined dolerite sheets is intersected by a radiating dyke-array associated with remnants of a phreatomagmatic vent, where the dolerite is locally quenched and mixed to form peperite. Intrusion geometries, and lack of dominant rift-related structures in the country rock indicate that magma overpressure, local stresses between mutually interacting dykes and vertical variations of host rock mechanical properties controlled the intrusive process throughout the thick and otherwise undeformed pile of sedimentary rocks (Victoria Group). Dolerite sills connected to one another by inclined sheets are inferred to record the preferred mode of propagation for magma-carrying cracks that represent the shallow portions of the Ferrar LIP plumbing system.
Corrections for interferences and extraction conditions make a difference: use of the TBARS assay for lipid peroxidation of orthodoxSpartina pectinataand recalcitrantSpartina alternifloraseeds during desiccation
Authors: Chappell James H. , Cohn Marc Alan 
Published: February 2011

AbstractLipid peroxidation and membrane damage are often proposed as causes of recalcitrant seed death, and the thiobarbituric acid reactive substances (TBARS) assay is commonly used to measure lipid peroxidation. However, several artefacts can cause an overestimation of TBARS values, and these have not been routinely addressed in experiments with recalcitrant seeds. In the present report, TBARS was assayed as recalcitrantSpartina alternifloraand orthodoxS. pectinataseeds were dried rapidly. Using the traditional Heath and Packer (1968) protocol with tissue extraction at 4°C,S. alterniflorahad higher overall TBARS values thanS. pectinata, and TBARS products increased when recalcitrantS. alternifloraand orthodoxS. pectinataseeds were dried. However, when corrections for interfering substances, such as sugars and anthocyanins, were made, the TBARS values between the two species were almost identical. When seeds were freeze-clamped in liquid nitrogen prior to extraction, TBARS did not increase during desiccation for either species. These findings may indicate that lipid peroxidation is not the cause of desiccation-induced death inS. alterniflora. Therefore, freeze-clamping during tissue extraction and corrections for TBARS interfering substances must be applied to avoid overestimation of lipid peroxidation values.
Substantial expression of mature elastin in arterial constructs
Authors: Lee Kee-Won , Stolz Donna B. , Wang Yadong 
Published: February 2011

Mature elastin synthesis is a key challenge in arterial tissue engineering. Most engineered vessels lack elastic fibers in the medial layer and those present are poorly organized. The objective of this study is to increase mature elastin synthesis in small-diameter arterial constructs. Adult primary baboon smooth muscle cells (SMCs) were seeded in the lumen of porous tubular scaffolds fabricated from a biodegradable elastomer, poly(glycerol sebacate) (PGS) and cultured in a pulsatile flow bioreactor for 3 wk. We tested the effect of pore sizes on construct properties by histological, biochemical, and mechanical evaluations. Histological analysis revealed circumferentially organized extracellular matrix proteins including elastin and the presence of multilayered SMCs expressing calponin and α-smooth muscle actin. Biochemical analysis demonstrated that the constructs contained mature elastin equivalent to 19% of the native arteries. Mechanical tests indicated that the constructs could withstand up to 200 mmHg burst pressure and exhibited compliance comparable to native arteries. These results show that nontransfected cells in PGS scaffolds in unsupplemented medium produced a substantial amount of mature elastin within 3 wk and the elastic fibers had similar orientation as those in native arteries. The 25–32 μm pore size supported cell organization and elastin synthesis more than larger pore sizes. To our knowledge, there was no prior report of the synthesis of mature and organized elastin in arterial constructs without exogenous factors or viral transduction.
Chemical storage of hydrogen in few-layer graphene
Authors: Subrahmanyam K. S. , Kumar Prashant , Maitra Urmimala , Govindaraj A. , Hembram K. P. S. S. , Waghmare Umesh V. , Rao C. N. R. 
Published: February 2011

Birch reduction of few-layer graphene samples gives rise to hydrogenated samples containing up to 5 wt % of hydrogen. Spectroscopic studies reveal the presence of sp
3
C-H bonds in the hydrogenated graphenes. They, however, decompose readily on heating to 500 °C or on irradiation with UV or laser radiation releasing all the hydrogen, thereby demonstrating the possible use of few-layer graphene for chemical storage of hydrogen. First-principles calculations throw light on the mechanism of dehydrogenation that appears to involve a significant reconstruction and relaxation of the lattice.
Radiation Exposure of the Anesthesiologist in the Neurointerventional Suite
Authors: Anastasian Zirka H. , Strozyk Dorothea , Meyers Philip M. , Wang Shuang , Berman Mitchell F. 
Published: February 2011

Background
Scatter radiation during interventional radiology procedures can produce cataracts in participating medical personnel. Standard safety equipment for the radiologist includes eye protection. The typical configuration of fluoroscopy equipment directs radiation scatter away from the radiologist and toward the anesthesiologist. This study analyzed facial radiation exposure of the anesthesiologist during interventional neuroradiology procedures.

Methods
Radiation exposure to the forehead of the anesthesiologist and radiologist was measured during 31 adult neuroradiologic procedures involving the head or neck. Variables hypothesized to affect anesthesiologist exposure were recorded for each procedure. These included total radiation emitted by fluoroscopic equipment, radiologist exposure, number of pharmacologic interventions performed by the anesthesiologist, and other variables.

Results
Radiation exposure to the anesthesiologist's face averaged 6.5 ± 5.4 μSv per interventional procedure. This exposure was more than 6-fold greater (P < 0.0005) than for noninterventional angiographic procedures (1.0 ± 1.0) and averaged more than 3-fold the exposure of the radiologist (ratio, 3.2; 95% CI, 1.8-4.5). Multiple linear regression analysis showed that the exposure of the anesthesiologist was correlated with the number of pharmacologic interventions performed by the anesthesiologist and the total exposure of the radiologist.

Conclusions
Current guidelines for occupational radiation exposure to the eye are undergoing review and are likely to be lowered below the current 100-150 mSv/yr limit. Anesthesiologists who spend significant time in neurointerventional radiology suites may have ocular radiation exposure approaching that of a radiologist. To ensure parity with safety standards adopted by radiologists, these anesthesiologists should wear protective eyewear.
Monitoring of Vital Signs for Long-Term Survival of Mice under Anesthesia: FIGURE 1.
Authors: Ewald Andrew J. , Werb Zena , Egeblad Mikala 
Published: February 2011

INTRODUCTIONAnesthesia protocols for mice have been optimized, as described here, to achieve long-term imaging (up to 40 h) and facilitate survival through careful monitoring of the mice during anesthesia. Isoflurane anesthesia is the preferred method, because it can be adjusted quickly as needed during the experiment. Critical for the long survival times under anesthesia is the use of the lowest possible dose of anesthesia, which is identified by corneal reflex and monitoring of breath and heart rate, blood-oxygenation levels, and vascular distension using an oximeter probe. It is critical that the carrier gas for isoflurane is humidified. In addition, it is essential to keep mice warm and to compensate for loss of fluid by supplementing with saline. Alternative approaches rely on injectable anesthetics, which do not require dedicated equipment or high-ventilation rates in the imaging room. However, injectable anesthetics are harder to dose for image sessions of >6-10 h.
Optical Coherence Tomography Imaging of Early Quail Embryos
Authors: Gu Shi , Jenkins Michael W. , Watanabe Michiko , Rollins Andrew M. 
Published: February 2011

INTRODUCTIONCongenital heart defects (CHDs) affect thousands of newborns each year in the United States. Recent research using animal model systems indicates that the abnormal function of the early tubular heart precedes structural defects such as septal defects. Optical coherence tomography (OCT) is an imaging modality that can provide high spatial and temporal resolution to study both the structure and the function of the tubular heart. With technical advances in OCT imaging speed, especially with frequency domain OCT and image-based retrospective gating, it is now possible to image a beating avian embryonic heart in three dimensions under physiological conditions and follow morphogenesis over critical periods of developmental time. These technological advances have already revealed novel aspects of heart development. By expanding our understanding of heart development, research using OCT technology combined with other imaging modalities may eventually lead to strategies to predict, treat, and even prevent CHDs. This protocol provides some practical details for obtaining four-dimensional (4D) OCT images from beating embryonic quail hearts, with the necessary temporal and spatial resolution.
Induction of an Immune Response for Imaging Antigen-Presenting Cell/T–Cell Interactions
Authors: Matheu Melanie P. , Cahalan Michael D. , Parker Ian 
Published: February 2011

INTRODUCTIONActivated dendritic cells (DCs) are the most efficient antigen-presenting cells (APCs) in the immune system. This protocol describes three different methods to activate antigen-specific CD4+ T cells using (i) bone-marrow-derived DCs, (ii) endogenous dermal DCs that drain to the local lymph node (LN), and (iii) tissue-resident APCs in a delayed-type hypersensitivity (DTH) response.
Labeling Lysosomes in Live Cells with LysoTracker
Authors: Chazotte Brad 
Published: February 2011

INTRODUCTIONThe LysoTracker probes (Invitrogen/Molecular Probes) are used to label lysosomes in live cells, as described in this protocol. They are more selective for acidic organelles than the classically used neutral red or acridine orange dyes. They are freely membrane permeant at neutral pH and effectively label lysosomes at nanomolar concentrations, with ~50 nM being optimal for selectivity. It has been reported that in larger acidic compartments, the staining pattern is preserved even after fixation with aldehydes. LysoTracker dyes can be visualized at different wavelengths, so they are useful when multiple fluorescent dyes are used to label cells simultaneously.
Apoplastic Alkalinization Is Instrumental for the Inhibition of Cell Elongation in the Arabidopsis Root by the Ethylene Precursor 1-Aminocyclopropane-1-Carboxylic Acid
Authors: Staal Marten , De Cnodder Tinne , Simon Damien , Vandenbussche Filip , Van Der Straeten Dominique , Verbelen Jean-Pierre , Elzenga Theo , Vissenberg Kris 
Published: February 2011

Abstract
In Arabidopsis (Arabidopsis thaliana; Columbia-0) roots, the so-called zone of cell elongation comprises two clearly different domains: the transition zone, a postmeristematic region (approximately 200–450 μm proximal of the root tip) with a low rate of elongation, and a fast elongation zone, the adjacent proximal region (450 μm away from the root tip up to the first root hair) with a high rate of elongation. In this study, the surface pH was measured in both zones using the microelectrode ion flux estimation technique. The surface pH is highest in the apical part of the transition zone and is lowest at the basal part of the fast elongation zone. Fast cell elongation is inhibited within minutes by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid; concomitantly, apoplastic alkalinization occurs in the affected root zone. Fusicoccin, an activator of the plasma membrane H+-ATPase, can partially rescue this inhibition of cell elongation, whereas the inhibitor N,N′-dicyclohexylcarbodiimide does not further reduce the maximal cell length. Microelectrode ion flux estimation experiments with auxin mutants lead to the final conclusion that control of the activity state of plasma membrane H+-ATPases is one of the mechanisms by which ethylene, via auxin, affects the final cell length in the root.
Metabolic and Transcriptomic Phenotyping of Inorganic Carbon Acclimation in the Cyanobacterium Synechococcus elongatus PCC 7942
Authors: Schwarz Doreen , Nodop Anke , Hüge Jan , Purfürst Stephanie , Forchhammer Karl , Michel Klaus-Peter , Bauwe Hermann , Kopka Joachim , Hagemann Martin 
Published: February 2011

Abstract
The amount of inorganic carbon is one of the main limiting environmental factors for photosynthetic organisms such as cyanobacteria. Using Synechococcus elongatus PCC 7942, we characterized metabolic and transcriptomic changes in cells that had been shifted from high to low CO2 levels. Metabolic phenotyping indicated an activation of glycolysis, the oxidative pentose phosphate cycle, and glycolate metabolism at lowered CO2 levels. The metabolic changes coincided with a general reprogramming of gene expression, which included not only increased transcription of inorganic carbon transporter genes but also genes for enzymes involved in glycolytic and photorespiratory metabolism. In contrast, the mRNA content for genes from nitrogen assimilatory pathways decreased. These observations indicated that cyanobacteria control the homeostasis of the carbon-nitrogen ratio. Therefore, results obtained from the wild type were compared with the MP2 mutant of Synechococcus 7942, which is defective for the carbon-nitrogen ratio-regulating PII protein. Metabolites and genes linked to nitrogen assimilation were differentially regulated, whereas the changes in metabolite concentrations and gene expression for processes related to central carbon metabolism were mostly similar in mutant and wild-type cells after shifts to low-CO2 conditions. The PII signaling appears to down-regulate the nitrogen metabolism at lowered CO2, whereas the specific shortage of inorganic carbon is recognized by different mechanisms.