bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Total Dissolved Gas on Chum Salmon Fry Survival, Growth, Gas Bubble Disease, and Seawater Tolerance
Authors: Geist David R. , Linley Timothy J. , Cullinan Valerie , Deng Zhiqun 
Published: February 2013

Abstract
Chum Salmon Oncorhynchus keta alevins developing in gravel downstream of Bonneville Dam on the Columbia River are exposed to elevated total dissolved gas (TDG) when water is spilled to move migrating salmon smolts to the ocean. We studied whether alevins that were exposed to six levels of dissolved gas ranging from 100% to 130% TDG at three development periods between hatch and emergence (hereafter, early, middle, and late stages) experienced differential mortality, growth, gas bubble disease, or seawater tolerance. Each life stage was exposed for 49 d (early stage), 28 d (middle stage), or 15 d (late stage) beginning at 13, 34, and 47 d posthatch, respectively, through emergence. Mortality for all stages was estimated to be 8% (95% confidence interval [CI] = 4–12%) when dissolved gas levels were less than 117% TDG. Mortality increased as dissolved gas levels rose above 117% TDG; the lethal concentration producing 50% mortality was 128.7% TDG (95% CI = 127.2–130.3% TDG) in the early and middle stages. There was no evidence that gas exposure affected growth. The proportion of fish with gas bubble disease increased with increasing gas concentrations, and bubbles occurred most commonly in the nares and gastrointestinal tract. Early stage fish exhibited higher ratios of filamental to lamellar gill chloride cells than late-stage fish, and these ratios increased and decreased for early and late-stage fish, respectively, as gas levels increased; however, there were no significant differences in mortality between life stages after 96 h in seawater. The study results suggest that water quality guidelines for dissolved gas (≤105% TDG) offer a conservative level of protection to Chum Salmon alevins incubating in gravel habitat downstream of Bonneville Dam.
Received June 1, 2012; accepted November 13, 2012
Using Notches to Uncover Optimization Frictions and Structural Elasticities: Theory and Evidence from Pakistan
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Authors: Kleven Henrik J. , Waseem Mazhar 
Published: February 2013

Abstract
We develop a framework for nonparametrically identifying optimization frictions and structural elasticities using notches—discontinuities in the choice sets of agents—introduced by tax and transfer policies. Notches create excess bunching on the low-tax side and missing mass on the high-tax side of a cutoff, and they are often associated with a region of strictly dominated choice that would have zero mass in a frictionless world. By combining excess bunching (observed response attenuated by frictions) with missing mass in the dominated region (frictions), it is possible to uncover the structural elasticity that would govern behavior in the absence of frictions and arguably capture long-run behavior. We apply our framework to tax notches in Pakistan using rich administrative data. While observed bunching is large and sharp, optimization frictions are also very large as the majority of taxpayers in dominated ranges are unresponsive to tax incentives. The combination of large observed bunching and large frictions implies that the frictionless behavioral response to notches is extremely large, but the underlying structural elasticity driving this response is nevertheless modest. This highlights the inefficiency of notches: by creating extremely strong price distortions, they induce large behavioral responses even when structural elasticities are small.
Forebrain HCN1 Channels Contribute to Hypnotic Actions of Ketamine
Authors: Zhou Cheng , Douglas Jennifer E. , Kumar Natasha N. , Shu Shaofang , Bayliss Douglas A. , Chen Xiangdong 
Published: February 2013

Abstract

Background:
Ketamine is a commonly used anesthetic, but the mechanistic basis for its clinically relevant actions remains to be determined. The authors previously showed that HCN1 channels are inhibited by ketamine and demonstrated that global HCN1 knockout mice are twofold less sensitive to hypnotic actions of ketamine. Although that work identified HCN1 channels as a viable molecular target for ketamine, it did not determine the relevant neural substrate.

Methods:
To localize the brain region responsible for HCN1-mediated hypnotic actions of ketamine, the authors used a conditional knockout strategy to delete HCN1 channels selectively in excitatory cells of the mouse forebrain. A combination of molecular, immunohistochemical, and cellular electrophysiologic approaches was used to verify conditional HCN1 deletion; a loss-of-righting reflex assay served to ascertain effects of forebrain HCN1 channel ablation on hypnotic actions of ketamine.

Results:
In conditional knockout mice, HCN1 channels were selectively deleted in cortex and hippocampus, with expression retained in cerebellum. In cortical pyramidal neurons from forebrain-selective HCN1 knockout mice, effects of ketamine on HCN1-dependent membrane properties were absent; notably, ketamine was unable to evoke membrane hyperpolarization or enhance synaptic inputs. Finally, the EC50 for ketamine-induced loss-of-righting reflex was shifted to significantly higher concentrations (by approximately 31%).

Conclusions:
These data indicate that forebrain principal cells represent a relevant neural substrate for HCN1-mediated hypnotic actions of ketamine. The authors suggest that ketamine inhibition of HCN1 shifts cortical neuron electroresponsive properties to contribute to ketamine-induced hypnosis.
Effects of Intratracheal Mesenchymal Stromal Cell Therapy during Recovery and Resolution after Ventilator-induced Lung Injury
Authors: Curley Gerard F. , Ansari Bilal , Hayes Mairead , Devaney James , Masterson Claire , Ryan Aideen , Barry Frank , O’Brien Timothy , Toole Daniel O’ , Laffey John G. 
Published: February 2013

Abstract

Background:
Mesenchymal stromal cells (MSCs) have been demonstrated to attenuate acute lung injury when delivered by intravenous or intratracheal routes. The authors aimed to determine the efficacy of and mechanism of action of intratracheal MSC therapy and to compare their efficacy in enhancing lung repair after ventilation-induced lung injury with intravenous MSC therapy.

Methods:
After induction of anesthesia, rats were orotracheally intubated and subjected to ventilation-induced lung injury (respiratory rate 18 min−1, P
insp 35 cm H2O,) to produce severe lung injury. After recovery, animals were randomized to receive: (1) no therapy, n = 4; (2) intratracheal vehicle (phosphate-buffered saline, 300 µl, n = 8); (3) intratracheal fibroblasts (4 × 106 cells, n = 8); (4) intratracheal MSCs (4 × 106 cells, n = 8); (5) intratracheal conditioned medium (300 µl, n = 8); or (6) intravenous MSCs (4 × 106 cells, n = 4). The extent of recovery after acute lung injury and the inflammatory response was assessed after 48 h.

Results:
Intratracheal MSC therapy enhanced repair after ventilation-induced lung injury, improving arterial oxygenation (mean ± SD, 146 ± 3.9 vs. 110.8 ± 21.5 mmHg), restoring lung compliance (1.04 ± 0.11 vs. 0.83 ± 0.06 ml·cm H2O−1), reducing total lung water, and decreasing lung inflammation and histologic injury compared with control. Intratracheal MSC therapy attenuated alveolar tumor necrosis factor-α (130 ± 43 vs. 488 ± 211 pg·ml−1) and interleukin-6 concentrations (138 ± 18 vs. 260 ± 82 pg·ml−1). The efficacy of intratracheal MSCs was comparable with intravenous MSC therapy. Intratracheal MSCs seemed to act via a paracine mechanism, with conditioned MSC medium also enhancing lung repair after injury.

Conclusions:
Intratracheal MSC therapy enhanced recovery after ventilation-induced lung injury via a paracrine mechanism, and was as effective as intravenous MSC therapy.
A Developmental Framework for Complex Plasmodesmata Formation Revealed by Large-Scale Imaging of the Arabidopsis Leaf Epidermis
Authors: Fitzgibbon Jessica , Beck Martina , Zhou Ji , Faulkner Christine , Robatzek Silke , Oparka Karl 
Published: February 2013

Abstract
Plasmodesmata (PD) form tubular connections that function as intercellular communication channels. They are essential for transporting nutrients and for coordinating development. During cytokinesis, simple PDs are inserted into the developing cell plate, while during wall extension, more complex (branched) forms of PD are laid down. We show that complex PDs are derived from existing simple PDs in a pattern that is accelerated when leaves undergo the sink–source transition. Complex PDs are inserted initially at the three-way junctions between epidermal cells but develop most rapidly in the anisocytic complexes around stomata. For a quantitative analysis of complex PD formation, we established a high-throughput imaging platform and constructed PDQUANT, a custom algorithm that detected cell boundaries and PD numbers in different wall faces. For anticlinal walls, the number of complex PDs increased with increasing cell size, while for periclinal walls, the number of PDs decreased. Complex PD insertion was accelerated by up to threefold in response to salicylic acid treatment and challenges with mannitol. In a single 30-min run, we could derive data for up to 11k PDs from 3k epidermal cells. This facile approach opens the door to a large-scale analysis of the endogenous and exogenous factors that influence PD formation.
Diversity and evolutionary relationships of T7‐like podoviruses infecting marine cyanobacteria
Authors: Dekel‐Bird Naama P. , Avrani Sarit , Sabehi Gazalah , Pekarsky Irina , Marston Marcia F. , Kirzner Shay , Lindell Debbie 
Published: February 2013

SummaryPhages are extremely abundant in the oceans, influencing the population dynamics, diversity and evolution of their hosts. Here we assessed the diversity and phylogenetic relationships among T7‐like cyanophages using DNA polymerase (replication), major capsid (structural) and photosynthesis psbA (host‐derived) genes from isolated phages. DNA polymerase and major capsid phylogeny divided them into two discrete clades with no evidence for gene exchange between clades. Clade A phages primarily infect Synechococcus while clade B phages infect either Synechococcus or Prochlorococcus. The major capsid gene of one of the phages from clade B carries a putative intron. Nearly all clade B phages encode psbA whereas clade A phages do not. This suggests an ancient separation between cyanophages from these two clades, with the acquisition or loss of psbA occurring around the time of their divergence. A mix and match of clustering patterns was found for the replication and structural genes within each major clade, even among phages infecting different host genera. This is suggestive of numerous gene exchanges within each major clade and indicates that core phage functions have not coevolved with specific hosts. In contrast, clustering of phage psbA broadly tracks that of the host genus. These findings suggest that T7‐like cyanophages evolve through clade‐limited gene exchanges and that different genes are subjected to vastly different selection pressures.
Empirical Evidence on the Implicit Determinants of Compensation in Big 4 Audit Partnerships
Authors: KNECHEL W. ROBERT , NIEMI LASSE , ZERNI MIKKO 
Published: February 2013

ABSTRACTThis study investigates the implicit financial incentives of individual Big 4 audit partners by examining the association between a partner's compensation and characteristics of the audit firm, audit partner, and individual partner clientele for Big 4 firms in Sweden. Using tax and financial data for individual audit partners and clients, our empirical findings indicate that there is significant variation in the implicit determinants that are associated with compensation across the Big 4. We find that audit partners’ compensation is positively associated with the size of their clientele or the number of publicly traded clients, both of which represent revenue‐generating opportunities. Similarly, compensation and developing an industry specialization are positively related. In three firms, gaining clients is clearly related to an increase in compensation, while losing a client is associated with a reduction in partner income in only one firm. We find that audit partner income is more sensitive to performance‐related incentives, such as attracting new clients, as partners progress in their career. Finally, we find evidence that audit failures, proxied by reporting errors related to issuing a going concern opinion, are associated with lower compensation. These results should be of interest to the auditing profession, audit firms, and regulators when they consider the effects of implicit incentives of partner compensation on audit quality.
Nitrogen losses from the soil/plant system: a review
Authors: Cameron K.C. , Di H.J. , Moir J.L. 
Published: February 2013

AbstractLosses of nitrogen from the soil/plant system not only reduce soil fertility and plant yield but can also create adverse impacts on the environment. Ammonia emissions into the atmosphere contribute to acid rain and represent an indirect source of nitrous oxide greenhouse gas emissions. Nitrate leaching losses into rivers and lakes can cause eutrophication resulting in excessive growth of aquatic weeds and algae, which can reduce fish populations and the recreational value of the water. Nitrate contamination of drinking water supplies can cause health risks. Legislation that is designed to limit nitrate leaching losses from land has become a constraint on agricultural land use in many countries. Nitrous oxide emissions into the atmosphere contribute to the depletion of the ozone layer and also make a significant contribution to climate change. This review describes the nitrogen cycle in temperate soil/plant systems, the processes involved in each of the individual nitrogen loss pathways, the factors affecting the amounts of losses and the methods that are available to reduce these losses. The review has shown that careful management of temperate soil/plant systems using best management practices and newly developed technologies can increase the sustainability of agriculture and reduce its impact on the environment.
Susceptibility of Prunus rootstocks against Marcus and Dideron isolates of Plum pox virus by graft‐inoculation
Authors: Rubio M. , Dicenta F. , Masse M. , Duval H. 
Published: February 2013

AbstractSharka (Plum pox virus, PPV) is one of the most important diseases affecting stone fruits. While there is much information on the reaction of cultivars to PPV infection, details about rootstocks are scarce. In this study, we evaluated 28 stone fruit rootstocks belonging to different Prunus species against the Marcus and Dideron strains of PPV. Rootstocks were evaluated under controlled conditions during two growing seasons using two inoculation methods: direct inoculation of own‐rooted rootstocks and grafting onto PPV‐infected GF305 peach seedlings. Our results showed a generalised susceptibility of the rootstocks evaluated. Evaluating own‐rooted rootstocks was more efficient than the traditional method of grafting onto infected GF305 seedlings. As expected, PPV‐M was found to be more aggressive than PPV‐D, producing symptoms and occurring in a higher number of plants, as shown by ELISA. The most susceptible rootstocks were Myran, Viking, Myro pg Pecher, Julior, Myrobolan 29C, Rubira, Myrobolan B, MrS 2/5, Jaspi and MP8. The least susceptible were GF677, Myrotop, Citation and ZH6. These results highlight the necessity to breed PPV‐resistant rootstocks for the different stone fruit species.
Primary human muscle precursor cells obtained from young and old donors produce similar proliferative, differentiation and senescent profiles in culture
Authors: Alsharidah Mansour , Lazarus Norman R. , George Tomasz E. , Agley Chibeza C. , Velloso Cristiana P. , Harridge Stephen D. R. 
Published: February 2013

SummaryThe myogenic behaviour of primary human muscle precursor cells (MPCs) obtained from young (aged 20–25 years) and elderly people (aged 67–82 years) was studied in culture. Cells were compared in terms of proliferation, DNA damage, time course and extent of myogenic marker expression during differentiation, fusion, size of the formed myotubes, secretion of the myogenic regulatory cytokine TGF‐β1 and sensitivity to TGF‐β1 treatment. No differences were observed between cells obtained from the young and elderly people. The cell populations were expanded in culture until replicative senescence. Cultures that maintained their initial proportion of myogenic cells (desmin positive) with passaging (n = 5) were studied and compared with cells from the same individuals in the non‐senescent state. The senescent cells exhibited a greater number of cells with DNA damage (γ‐H2AX positive), showed impaired expression of markers of differentiation, fused less well, formed smaller myotubes and secreted more TGF‐β. The data strongly suggest that MPCs from young and elderly people have similar myogenic behaviour.
China's regional agricultural productivity growth in 1985–2007: A multilateral comparison1
Authors: Wang Sun Ling , Tuan Francis , Gale Fred , Somwaru Agapi , Hansen James 
Published: February 2013

AbstractIn this study, we estimate total factor productivity (TFP) growth as well as multilateral TFP index for 25 contiguous China provinces over the 1985–2007 period. Agricultural output growth for each province was decomposed into TFP growth and input growth, where input growth was further disaggregated into contributions from growth of labor, capital, land, and intermediate goods. Over the study period, TFP growth contributed 2.7 percentage points to output growth annually, which was slightly higher than the input growth contribution of 2.4 percentage points per annum. On average, the annual rate of productivity growth peaked during 1996–2000, at 5.1%. It slowed in 2000–2005 to a rate of 3.2% per annum and declined in the most recent years (2005–2007) to −3.7%. Differences in productivity among regions persisted over the entire period. The tendency toward faster TFP growth in relatively well‐off coastal regions may imply a widening of regional inequality.
So Close, So Far Away: Analysis of Surnames in a Town of Twins (Cândido Godói, Brazil)
Authors: De Oliveira Marcelo Zagonel , Schüler‐Faccini Lavínia , Demarchi Dario A. , Alfaro Emma L. , Dipierri José E. , Veronez Mauricio R. , Colling Cassel Marlise , Tagliani‐Ribeiro Alice , Silveira Matte Ursula , Ramallo Virginia 
Published: February 2013

SummaryCândido Godói is a small Brazilian town known for high rates of twin birth. In 2011, a genetic study showed that this localized high rate of twin births could be explained by a genetic founder effect. Here we used isonymic analysis and surname distribution to identify population subgroups within 5316 inhabitants and 665 different surnames. Four clusters were constructed based on different twin rates (P< 0.001; MRPP test). Fisher'sαand consanguinity index showed low and high values, respectively, corresponding with observed values in isolated communities with high levels of genetic drift. Values ofAandBestimators confirmed population isolation. Three boundaries were identified with Monmonier's maximum difference algorithm (P= 0.007). Inside the isolated sections, surnames of different geographic origins, language, and religion were represented. With an adequate statistical methodology, surname analyses provided a close approximation of historic and socioeconomic background at the moment of colony settlement. In this context, the maintenance of social and cultural practices had strong implications for the population's structure leading to drift processes in this small town, supporting the previous genetic study.
Movement, activity and hunting behaviour of leopards in the Cederberg mountains, South Africa
Authors: Martins Quinton , Harris Stephen 
Published: February 2013

AbstractFew data are available on the behaviour of leopards in the absence of competing large predators and human impact, both of which are believed to influence leopard activity and movements. Remote camera traps and global positioning system (GPS) collars were used to quantify leopard activity in the Cederberg Mountains, seasonal and sexual differences in their movements, and determine whether nocturnal hunting success was related to lunar activity. Seventy‐seven per cent of camera‐trap photographs were at night, with a strong male bias (69%) in captures. Daily displacement using one location per day suggested that males moved significantly further than females. However, multiple locations (≥6 per day) showed no difference because males moved in a more linear fashion, but not further each day, than females. In the Cederberg Mountains, an open rocky habitat with low human impact and no competing predators, leopards were predominantly nocturnal, mainly hunting diurnal prey species. Hunting success was low: leopards travelled long distances between kills, with nocturnal hunting success higher on darker nights.
Farm‐derived Gram‐positive bacterium Staphylococcus sciuri W620 prevents asthma phenotype in HDM‐ and OVA‐exposed mice
Authors: Hagner S. , Harb H. , Zhao M. , Stein K. , Holst O. , Ege M. J. , Mayer M. , Matthes J. , Bauer J. , von Mutius E. , Renz H. , Heine H. , Pfefferle P. I. , Garn H. 
Published: February 2013

AbstractBackgroundFarm‐derived dust samples have been screened for bacteria with potential allergo‐protective properties. Among those was Staphylococcus sciuri W620 (S. sciuri W620), which we tested with regard to its protective capacities in murine models of allergic airway inflammation.MethodsWe employed two protocols of acute airway inflammation in mice administering either ovalbumin (OVA) or house dust mite extract (HDM) for sensitization. Mechanistic studies on the activation of innate immune responses to S. sciuri W620 were carried out using human primary monocytic dendritic cells (moDC) and co‐culture with autologous T cells.ResultsThe allergo‐protective properties of S. sciuri W620 were proven in a TH2‐driven OVA model as well as in a mixed TH1/TH2 phenotype HDM model as demonstrated by abrogation of eosinophils and neutrophils in the airways after intranasal treatment. In the HDM model, lymph node cell TH1/TH2 signature cytokines were decreased in parallel. Studies on human moDC revealed an activation of TLR2 and NOD2 receptors and initiation of DC maturation following incubation with S. sciuri W620. Cytokine expression analyses after exposure to S. sciuri W620 showed a lack of IL‐12 production in moDC due to missing transcription of the IL‐12p35 mRNA. However, such DC selectively supported TH1 cytokine release by co‐cultured T cells.Conclusion and clinical relevanceOur proof‐of‐concept experiments verify the screening system of farm‐derived dust samples as suitable to elucidate new candidates for allergo‐protection. S. sciuri W620 was shown to possess preventive properties on airway inflammation providing the basis for further mechanistic studies and potential clinical implication.