bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural Determinants of the Interaction between the TpsA and TpsB Proteins in the Haemophilus influenzae HMW1 Two-Partner Secretion System
Authors: Grass Susan , Rempe Katherine A. , St. Geme Joseph W.
Published: March 2015

The two-partner secretion (TPS) pathway in Gram-negative bacteria consists of a TpsA exoprotein and a cognate TpsB outer membrane pore-forming translocator protein. Previous work has demonstrated that the TpsA protein contains an N-terminal TPS domain that plays an important role in targeting the TpsB protein and is required for secretion. The nontypeable
Haemophilus influenzae
HMW1 and HMW2 adhesins are homologous proteins that are prototype TpsA proteins and are secreted by the HMW1B and HMW2B TpsB proteins. In the present study, we sought to define the structural determinants of HMW1 interaction with HMW1B during the transport process and while anchored to the bacterial surface. Modeling of HMW1B revealed an N-terminal periplasmic region that contains two polypeptide transport-associated (POTRA) domains and a C-terminal membrane-localized region that forms a pore. Biochemical studies demonstrated that HMW1 engages HMW1B via interaction between the HMW1 TPS domain and the HMW1B periplasmic region, specifically, the predicted POTRA1 and POTRA2 domains. Subsequently, HMW1 is shuttled to the HMW1B pore, facilitated by the N-terminal region, the middle region, and the NPNG motif in the HMW1 TPS domain. Additional analysis revealed that the interaction between HMW1 and HMW1B is highly specific and is dependent upon the POTRA domains and the pore-forming domain of HMW1B. Further studies established that tethering of HMW1 to the surface-exposed region of HMW1B is dependent upon the external loops of HMW1B formed by residues 267 to 283 and residues 324 to 330. These observations may have broad relevance to proteins secreted by the TPS pathway.

IMPORTANCE
Secretion of HMW1 involves a recognition event between the extended form of the HMW1 propiece and the HMW1B POTRA domains. Our results identify specific interactions between the HMW1 propiece and the periplasmic HMW1B POTRA domains. The results also suggest that the process of HMW1 translocation involves at least two discrete steps, including initial interaction between the HMW1 propiece and the HMW1B POTRA domains and then a separate translocation event. We have also discovered that the HMW1B pore itself appears to influence the translocation process. These observations extend our knowledge of the two-partner secretion system and may be broadly relevant to other proteins secreted by the TPS pathway.
A Cluster of Four Homologous Small RNAs Modulates C
1
Metabolism and the Pyruvate Dehydrogenase Complex in Rhodobacter sphaeroides under Various Stress Conditions
Authors: Billenkamp Fabian , Peng Tao , Berghoff Bork A. , Klug Gabriele
Published: March 2015

In bacteria, regulatory RNAs play an important role in the regulation and balancing of many cellular processes and stress responses. Among these regulatory RNAs,
trans
-encoded small RNAs (sRNAs) are of particular interest since one sRNA can lead to the regulation of multiple target mRNAs. In the purple bacterium
Rhodobacter sphaeroides
, several sRNAs are induced by oxidative stress. In this study, we focused on the functional characterization of four homologous sRNAs that are cotranscribed with the gene for the conserved hypothetical protein RSP_6037, a genetic arrangement described for only a few sRNAs until now. Each of the four sRNAs is characterized by two stem-loops that carry CCUCCUCCC motifs in their loops. They are induced under oxidative stress, as well as by various other stress conditions, and were therefore renamed here sRNAs CcsR1 to CcsR4 (CcsR1–4) for
c
onserved
C
CUCCUCCC motif
s
tress-induced
R
NAs 1 to 4. Increased CcsR1–4 expression decreases the expression of genes involved in C
1
metabolism or encoding components of the pyruvate dehydrogenase complex either directly by binding to their target mRNAs or indirectly. One of the CcsR1–4 target mRNAs encodes the transcriptional regulator FlhR, an activator of glutathione-dependent methanol/formaldehyde metabolism. Downregulation of this glutathione-dependent pathway increases the pool of glutathione, which helps to counteract oxidative stress. The FlhR-dependent downregulation of the pyruvate dehydrogenase complex reduces a primary target of reactive oxygen species and reduces aerobic electron transport, a main source of reactive oxygen species. Our findings reveal a previously unknown strategy used by bacteria to counteract oxidative stress.

IMPORTANCE
Phototrophic organisms have to cope with photo-oxidative stress due to the function of chlorophylls as photosensitizers for the formation of singlet oxygen. Our study assigns an important role in photo-oxidative stress resistance to a cluster of four homologous sRNAs in the anoxygenic phototrophic bacterium
Rhodobacter sphaeroides
. We reveal a function of these regulatory RNAs in the fine-tuning of C
1
metabolism. A model that relates oxidative stress defense to C
1
metabolism is presented.
Neisseria gonorrhoeae MutS Affects Pilin Antigenic Variation through Mismatch Correction and Not by
pilE
Guanine Quartet Binding
Authors: Rotman Ella , Seifert H. Steven
Published: March 2015

Many pathogens use homologous recombination to vary surface antigens to avoid immune surveillance.
Neisseria gonorrhoeae
achieves this in part by changing the properties of its surface pili in a process called pilin antigenic variation (AV). Pilin AV occurs by high-frequency gene conversion reactions that transfer silent
pilS
sequences into the expressed
pilE
locus and requires the formation of an upstream guanine quartet (G4) DNA structure to initiate this process. The MutS and MutL proteins of the mismatch correction (MMC) system act to correct mismatches after replication and prevent homeologous (i.e., partially homologous) recombination, but MutS orthologs can also bind to G4 structures. A previous study showed that mutation of MutS resulted in a 3-fold increase in pilin AV, which could be due to the loss of MutS antirecombination properties or loss of G4 binding. We tested two site-directed separation-of-function MutS mutants that are both predicted to bind to G4s but are not able to perform MMC. Pilus phase variation assays and DNA sequence analysis of
pilE
variants produced in these mutants showed that all three
mutS
mutants and a
mutL
mutant had similar increased frequencies of pilin AV. Moreover, the
mutS
mutants all showed similar increased levels of pilin AV-dependent synthetic lethality. These results show that antirecombination by MMC is the reason for the effect that MutS has on pilin AV and is not due to
pilE
G4 binding by MutS.

IMPORTANCE
Neisseria gonorrhoeae
continually changes its outer surface proteins to avoid recognition by the immune system.
N. gonorrhoeae
alters the antigenicity of the pilus by directed recombination between partially homologous pilin copies in a process that requires a guanine quartet (G4) structure. The MutS protein of the mismatch correction (MMC) system prevents recombination between partially homologous sequences and can also bind to G4s. We confirmed that loss of MMC increases the frequency of pilin antigenic variation and that two MutS mutants that are predicted to separate the two different functions of MutS inhibit pilin variation similarly to a complete-loss-of-function mutant, suggesting that interaction of MutS with the G4 structure is not a major factor in this process.
Mutations in Pneumococcal
cpsE
Generated via
In Vitro
Serial Passaging Reveal a Potential Mechanism of Reduced Encapsulation Utilized by a Conjunctival Isolate
Authors: Shainheit Mara G. , Valentino Michael D. , Gilmore Michael S. , Camilli Andrew
Published: March 2015

The polysaccharide capsule of
Streptococcus pneumoniae
is required for nasopharyngeal colonization and for invasive disease in the lungs, blood, and meninges. In contrast, the vast majority of conjunctival isolates are acapsular. The first serotype-specific gene in the capsule operon,
cpsE
, encodes the initiating glycosyltransferase and is one of the few serotype-specific genes that can tolerate null mutations. This report characterizes a spontaneously arising TIGR4 mutant exhibiting a reduced capsule, caused by a 6-nucleotide duplication in
cpsE
which results in duplication of Ala and Ile at positions 45 and 46. This strain (AI45dup) possessed more exposed phosphorylcholine and was hypersusceptible to C3 complement deposition compared to the wild type. Accordingly, the mutant was significantly better at forming abiotic biofilms and binding epithelial cells
in vitro
but was avirulent in a sepsis model.
In vitro
serial passaging of the wild-type strain failed to reproduce the AI45dup mutation but instead led to a variety of mutants with reduced capsule harboring single nucleotide polymorphisms (SNPs) in
cpsE
. A single passage in the sepsis model after high-dose inoculation readily yielded revertants of AI45dup with restored wild-type capsule level, but the majority of SNP alleles of
cpsE
could not revert, suppress, or bypass. Analysis of
cpsE
in conjunctival isolates revealed a strain with a single missense mutation at amino acid position 377, which was responsible for reduced encapsulation. This study supports the hypothesis that spontaneous, nonreverting mutations in
cpsE
serve as a form of adaptive mutation by providing a selective advantage to
S. pneumoniae
in niches where expression of capsule is detrimental.

IMPORTANCE
While the capsule of
Streptococcus pneumoniae
is required for colonization and invasive disease, most conjunctival isolates are acapsular by virtue of deletion of the entire capsular operon. We show that spontaneous acapsular mutants isolated
in vitro
harbor mostly nonrevertible single nucleotide polymorphism (SNP) null mutations in
cpsE
, encoding the initiating glycosyltransferase. From a small collection of acapsular conjunctival isolates, we identified one strain with a complete capsular operon but containing a SNP in
cpsE
that we show is responsible for the acapsular phenotype. We propose that acapsular conjunctival isolates may arise initially from such nonreverting SNP null mutations in
cpsE
, which can be followed later by deletion of portions or all of the
cps
operon.
Prevalence, risk factors and associations of primary Raynaud's phenomenon: systematic review and meta-analysis of observational studies
Authors: Garner Rozeena , Kumari Rakesh , Lanyon Peter , Doherty Michael , Zhang Weiya
Published: March 2015

Objective

To systematically review the literature with regard to the prevalence, incidence, risk factors and associations of primary Raynaud's phenomenon (PRP).

Method

A systematic review of the literature of observational studies for PRP was undertaken using five electronic databases. Any studies reporting prevalence, incidence and risk factors of PRP were collected. Relative risk or OR and 95% CI were extracted or calculated to present the association between risk factors and PRP. Random effects model was used to pool the results.

Results

33 articles assessing a total of 33 733 participants were included in this analysis (2 cohort, 17 cross-sectional and 14 case–control studies). The pooled prevalence of PRP was 4.85% (95% CI 2.08% to 8.71%) in the general population. The pooled annual incidence of PRP was 0.25% (95% CI 0.19% to 0.32%). Risk factors and associations for PRP included female gender (OR=1.65, 95% CI 1.42 to 1.91), family history (OR=16.6, 95% CI 7.44 to 36.8), smoking (OR=1.27, 95% CI 1.06 to 1.53), manual occupation (OR=2.66 95% CI 1.73 to 4.08), migraine (OR=4.02, 95% CI 2.62 to 6.17), cardiovascular disease (OR=1.69, 95% CI 1.22 to 2.34) and marital status (married, OR=0.60, 95% CI 0.43 to 0.83). The definition of PRP varied considerably between studies.

Conclusions

This is the first systematic review of the prevalence, incidence, risk factors and associations of PRP. Further study using uniform strict criteria for the condition is required to confirm these findings, particularly the possible association with cardiovascular disease.
Influence of tree species and salvaged soils on the recovery of ectomycorrhizal fungi in upland boreal forest restoration after surface mining
Authors: Hankin Shanon L. , Karst Justine , Landhäusser Simon M.
Published: March 2015

Surface mining in the Canadian boreal forest involves the removal of vegetation and soils, resulting in the local loss of biodiversity and ecosystem functioning. Ectomycorrhizal (EM) fungi are critical to ecosystem processes; however, their recovery following reclamation is not well understood. This study investigated the importance of reclamation cover soils (forest floor material, peat, and subsoil) and tree seedling species (Populus tremuloides Michx., Pinus banksiana Lamb., and Picea glauca (Moench) Voss) in structuring the community composition of EM fungi. We used 1-year-old seedlings to assay cover soils in the field for 3 months, and grew seedlings in each of the cover soils in a growth chamber assay for 5 months. Nonmetric multidimensional scaling indicated host identity structured the community composition of EM fungi in the field, while both host identity and cover soil influenced the composition of EM fungi in the growth chamber. However, pre-colonization of seedlings by nursery fungi complicates interpretation of field results. The rate of EM fungus colonization of seedlings collected across both assays was relatively low, approximately 23%. Our results indicate cover soils used in reclamation of surface-mined landscapes retain propagules of EM fungi, and using a wide variety of tree species in upland boreal forest restoration may increase the diversity of EM fungi recovered.
Genetic divergence and phylogeography of the alpine plant taxonOnobrychis transsilvanica(Fabaceae)
Authors: Bãcilã Ioan , Şuteu Dana , Coldea Gheorghe
Published: March 2015

Although the Carpathians represent one of the main elements of the European Alpine System and an important area of endemism, only a few phylogeographic studies concerning this region have focused on the detailed intraspecific variation in alpine plant species. Using two molecular marker systems, we (1) aimed to elucidate the controversy concerning the status of the endemic Carpathian taxon Onobrychis transsilvanica Simonk. in relation to the more widespread Onobrychis montana DC. and (2) determined the phylogeographic structure of O. transsilvanica within the Carpathians. For O. transsilvanica, our data suggest either a recent postglacial speciation with incomplete lineage sorting or genetic divergence followed by subsequent continuous gene flow during the glacial period. The genetic structure of the complex does not support O. transsilvanica as a distinct species from O. montana. Within the Carpathians, the extant populations of O. transsilvanica comprise two major allopatric lineages, which have been isolated from each other for a long period of time. Unexpectedly, the major genetic break was not in line with a classical biogeographical boundary in the Carpathians but rather separated a group from the southwestern edge of the mountains. We also discovered an additional divergent haplotype lineage, with weaker genetic support, within the O. transsilvanica populations.
Trichosanthes kirilowiiFruits Inhibit Non-Small Cell Lung Cancer Cell Growth Through Mitotic Cell-Cycle Arrest
Authors: Ni Lulu , Zhu Xiaowen , Gong Chenyuan , Luo Yinbin , Wang Lixin , Zhou Wuxiong , Zhu Shiguo , Li Yan
Published: March 2015

Lung cancer is the leading cause of cancer-related death worldwide. Non-small cell lung cancer (NSCLC) accounts for 80% of lung cancer cases and the reported overall 5-year survival rate is less than 5%. Natural medicines have attracted much attention due to their lower toxicity and fewer side effects. Trichosanthes kirilowii Maxim (TKM) fruits are commonly used in cancer treatment in combination with other Chinese medicinal herbs. However, little is known about their biological functions and mechanisms in NSCLC cells. In this study, we investigated the efficacy of TKM fruits in NSCLC cells using cell proliferation, invasion, migration, and anchorage independent assays and a Xenograft NSCLC tumor model, and explored the possible biological mechanism by flow cytometric analysis, cDNA microarray and real-time PCR. Results showed that TKM fruits significantly suppressed NSCLC cell proliferation, migration, invasion, tumorigenicity and tumor growth, and significantly extended the survival time of NSCLC-bearing mice. Flow cytometric analysis showed that TKM fruits significantly induced G2-M arrest, necrosis and apoptosis in NSCLC cells. cDNA microarray analysis revealed that TKM fruits regulated the differential expression of 544 genes, and the differential expression of selected genes was also confirmed. Gene ontology (GO) analysis showed that 18 of first 20 biological processes were involved in cell cycle and mitosis. These results indicate that TKM fruits have certain inhibitory effect on NSCLC cells through cell-cycle and mitosis arrest, and suggest that TKM fruits may be an important resource for developing new antitumor drugs, and a potent natural product for treating patients with NSCLC.
NOTE ON THE NUMBER OF OBTUSE ANGLES IN POINT SETS
Authors: FABILA-MONROY RUY , HUEMER CLEMENS , TRAMUNS EULÀLIA
Published: March 2015

In 1979 Conway, Croft, Erdős and Guy proved that every set S of n points in general position in the plane determines at least [Formula: see text] obtuse angles and also presented a special set of n points to show the upper bound [Formula: see text] on the minimum number of obtuse angles among all sets S. We prove that every set S of n points in convex position determines at least [Formula: see text] obtuse angles, hence matching the upper bound (up to sub-cubic terms) in this case. Also on the other side, for point sets with low rectilinear crossing number, the lower bound on the minimum number of obtuse angles is improved.
CONTINUOUS SURVEILLANCE OF POINTS BY ROTATING FLOODLIGHTS
Authors: BEREG S. , DÍAZ-BÁÑEZ J. M. , FORT M. , LOPEZ M. A. , PÉREZ-LANTERO P. , URRUTIA J.
Published: March 2015

Let P and F be sets of n ≥ 2 and m ≥ 2 points in a plane, respectively. We study the problem of finding the minimum angle α ϵ [2Π/m, 2Π] such that one can install at each point of F a stationary rotating floodlight with illumination angle α, initially oriented in a suitable direction, in such a way that, at all times, every target point of P is illuminated by at least one floodlight. All floodlights rotate clockwise at unit speed. We provide bounds for the case in which the elements of P ⋃ F are on a given line, and present exact results for the case in the plane in which we have two floodlights and many target points. We further consider the non-rotating version of the problem and look for the minimum angle α such that one can install a non-rotating floodlight with illumination angle α at each point of F, in such a way that every target point of P is illuminated by at least one floodlight. We show that this problem is NP-hard and hard to approximate.
A POLYNOMIAL-TIME ALGORITHM FOR COMPUTING THE RESILIENCE OF ARRANGEMENTS OF RAY SENSORS
Authors: KIRKPATRICK DAVID , YANG BOTING , ZILLES SANDRA
Published: March 2015

Given an arrangement A of n sensors and two points s and t in the plane, the barrier resilience of A with respect to s and t is the minimum number of sensors whose removal permits a path from s to t such that the path does not intersect the coverage region of any sensor in A. When the surveillance domain is the entire plane and sensor coverage regions are unit line segments, even with restricted orientations, the problem of determining the barrier resilience is known to be NP-hard. On the other hand, if sensor coverage regions are arbitrary lines, the problem has a trivial linear time solution. In this paper, we study the case where each sensor coverage region is an arbitrary ray, and give an O(n2m) time algorithm for computing the barrier resilience when there are m ⩾ 1 sensor intersections.
Dynamic Interaction Between Rigid Surface Foundations on Multi-Layered Half Space
Authors: Chen Lin
Published: March 2015

A numerical approach is presented to calculate the dynamic response of a group of rigid surface foundations. The formulation is unconditionally stable and has the computational simplicity with only the algebraic calculations involved. It imposes no limit to the foundation shape, foundation separations, thickness of the layered medium and magnitude of frequency. In the analysis, the foundation–ground interface is discretized into a number of sub square-regions. The Green’s function, which is obtained by the Fourier–Bessel transform and precise integration method, is employed to calculate the dynamic response of each sub-region. Finally, a system of linear algebraic equation in terms of the contact forces within each sub-region is observed, which leads to the desired dynamic impedance functions of the foundations. Comparison is carried out between the proposed method and the solutions available in the literature. Parametric studies on the dynamic interaction between adjacent foundations are also described. Addressed in this study are the effects of the distance and direction of foundation alignment. Several conclusions are drawn the significance of each factor. Illustrative results for a case of several closely-spaced foundations are also presented. Although the dynamic interaction analysis of foundations is concerned here, further applications of this approach can be extended to the interaction analysis of structures.
东南亚难侨归国后的心理适应
Authors: 林瑞恺  , 陈心洁
Published: March 2015

东南亚华人传承中华传统文化，又与在地国文化紧密融合，形成了自己的文化特色。从20世纪50年代初开始，大批东南亚华侨直接或间接地受到排华运动的影响，回到中国大陆。当时中国政府将这些归国难侨集中安置在南部几个省份的“华侨农场”。基于“含摄文化的心理学”(culture-inclusive psychology)，笔者尝试去解读这些难侨归国后的心声。本论文采用质性文本研究法(qualitative textual analysis)，分析《竹坝沧桑》（厦门华侨历史学会整理的人类学口述历史访谈录）中十个归国难侨回忆录个案，关注他们回到大陆后的涵化经历，以及面对涵化困难的应对策略。文本通过团队审核的方式为若干个相关主题进行编码， 并记录出现频率。归侨的适应经历分成三个时间段来探讨 — 归国初期、归国中期、归国后期，各具明显的阶段性特征。其应对策略体现了三个主题 — 社会支持、消极应对、积极应对。研究显示，积极应对的频率最高，表示这些难侨们能调动内心中的正向资源来应对文化冲击。虽然大部分难侨都选择留在农场，但大多依然存在很大的外来感，感到边缘化，使用自己的方言来生活。研究也发现，母语、原有社会阶级、教育水平在他们适应中国社会的时候起到了双刃剑的作用。
The Military Role in China's Foreign Policy-Making
Authors: YOU Ji
Published: March 2015

The PLA role in China's foreign policy is integral and deep. Politically it follows overall civilian primacy in foreign policy-making. Militarily the PLA sticks to assertiveness/war aversion dynamics in tackling external security threats, especially over territorial disputes. Functionally, the PLA abides by a top-down division of labour with diplomats. The PLA role in foreign policy-making can be overtly influential, as national/security/military-related foreign affairs are generally more important.
Does Privatisation Affect Earnings Management of State-owned Enterprises in China?
Authors: CHEN Chien-Hsun
Published: March 2015

Once privatised, SOEs are operating in a market with free competition; their reported earnings become an important indicator of the enterprise's operational performance. The degree of control that the state is able to exert over the company will diminish after privatisation. The concentrated ownership structure and the strong political and economic connections between the government and listed companies are the main causes of earnings management in China.
China's State-owned Enterprise Mixed Ownership Reform
Authors: ZHENG Yu
Published: March 2015

The new state-owned enterprise (SOE) mixed ownership reform have some distinct features that were not addressed in previous reforms. While some central SOEs and local governments have unveiled their own plans to diversify ownership structure, the success of the reform hinges on how the government resolves two credibility problems: one is to restore credibility to the reform commitment and the other is to convince private investors that their interests will be sufficiently protected.
Women's Participation in China's Budgeting Process
Authors: GUO Xiajuan
Published: March 2015

Participatory gender budget (PGB) has been in practice in China since 2005. Three PGB models have evolved: the “outsider model”, the “insider model” and the “integrated model”. Among the three, Zhejiang's Wenling experiment is unique due to its introduction of the “democratic consultation meeting”; it has accelerated the fulfilment of government's commitment to gender equality, executed some adjustments to the government budget, enhanced equal resource distribution and empowered women in the budget-making process.
China Upgrades Bilateral Investment Treaties to Promote its Growing Outbound Investment
Authors: TONG Sarah Y
Published: March 2015

Being a major recipient and an important source of foreign direct investment (FDI), China shifted its policy focus from attracting FDI inflow to facilitating and protecting outbound FDI. The shift is reflected in China's efforts to negotiate and to upgrade its bilateral investment treaties (BITs), especially the decision to revive the China-US BIT negotiations. This is important as the United States has become a significant designation for China's outbound FDI; numerous challenges however remain.
Rising Terrorism and China's New Policy in Xinjiang
Authors: SHAN Wei , PING Xiaojuan
Published: March 2015

Since May 2014 Beijing has started to push its two-pronged new policy plans in anti-terrorism and social development in Xinjiang after a series of Uighur-initiated violent terrorist attacks. One involves heavy-handed tactics and fierce crackdown campaign. The other is the announcement of a new social and economic policy package, including promoting Chinese national “consciousness” among ethnic minorities, boosting employment with a “one household, one job” policy and promoting bilingualism in Xinjiang's education policy.
Xi Jinping's Generals
Authors: BO Zhiyue
Published: March 2015

Since he became commander-in-chief in November 2012, Xi Jinping has promoted altogether 11 generals in three batches. The promotion of the third batch came in the shadow of expelling Xu Caihou, former vice chairman of the Central Military Commission and Politburo member, from the Party. In the future, Xi Jinping will have to strike a balance between the anti-corruption campaign in the military and the establishment of a core support group in the People's Liberation Army.
Laboratory characterization and pilot site tests of residual sludge from dimension stones for civil and environmental applications
Authors: Dino Giovanna Antonella , Lasagna Manuela , Clemente Paolo , De Luca Domenico Antonio
Published: March 2015

Residual sludge from dimension-stone working plants, both from gangue saws with abrasive shot and frame saws, is classified as waste and presents a number of problems for the stone industry. These problems include a fine size distribution, heavy metals and total petroleum hydrocarbon (TPH) content, all of which impede recovery and reuse. Residual sludge, management of which is administered in accordance with the Italian Legislative Decree 152/06, can be used in waste form for environmental restoration or for cement plants. However, it is also possible that sludge applications could go beyond these limited uses with incorporation of systematic treatment for the production of secondary raw materials (SRM), for example, filler, or for ‘new products’, for example, artificial loam. Such new products or SRM have to be certified not only on the basis of their technical and physical characteristics but also by means of appropriate chemical analyses to guarantee that the products are not contaminated.

This paper outlines the results from laboratory and
in situ
characterization of residual sludge. In particular, three potential applications of sludge either by itself or mixed with other materials were evaluated: landfill waterproofing material, filler material for civil works and artificial soil for land rehabilitation.
Aggregate Characterization of User Behavior in Twitter and Analysis of the Retweet Graph
Authors: Bild David R. , Liu Yue , Dick Robert P. , Mao Z. Morley , Wallach Dan S.
Published: March 2015

Most previous analysis of Twitter user behavior has focused on individual information cascades and the social followers graph, in which the nodes for two users are connected if one follows the other. We instead study aggregate user behavior and the retweet graph with a focus on quantitative descriptions. We find that the lifetime tweet distribution is a type-II discrete Weibull stemming from a power law hazard function, that the tweet rate distribution, although asymptotically power law, exhibits a lognormal cutoff over finite sample intervals, and that the inter-tweet interval distribution is a power law with exponential cutoff. The retweet graph is small-world and scale-free, like the social graph, but less disassortative and has much stronger clustering. These differences are consistent with it better capturing the real-world social relationships of and trust between users than the social graph. Beyond just understanding and modeling human communication patterns and social networks, applications for alternative, decentralized microblogging systems---both predicting real-word performance and detecting spam---are discussed.
P2P-Based, Multi-Attribute Resource Discovery under Real-World Resources and Queries
Authors: Bandara H. M. N. Dilum , Jayasumana Anura P.
Published: March 2015

Collaborative peer-to-peer (P2P), grid, and cloud computing rely on resource discovery (RD) solutions to aggregate groups of multi-attribute, dynamic, and distributed resources. However, specific characteristics of real-world resources and queries, and their impact on P2P-based RD, are largely unknown. We analyze the characteristics of resources and queries using data from four real-world systems. These characteristics are then used to qualitatively and quantitatively evaluate the fundamental design choices for P2P-based multi-attribute RD. The datasets exhibit several noteworthy features that affect the performance. For example, compared to uniform queries, real-world queries are relatively easier to resolve using unstructured, superpeer, and single-attribute-dominated query-based structured P2P solutions, as queries mostly specify only a small subset of the available attributes and large ranges of attribute values. However, all the solutions are prone to significant load balancing issues, as the resources and queries are highly skewed and correlated. The implications of our findings for improving RD solutions are also discussed.
In VitroStudies of Neuronal Networks and Synaptic Plasticity in Invertebrates and in Mammals Using Multielectrode Arrays
Authors: Massobrio Paolo , Tessadori Jacopo , Chiappalone Michela , Ghirardi Mirella
Published: March 2015

Brain functions are strictly dependent on neural connections formed during development and modified during life. The cellular and molecular mechanisms underlying synaptogenesis and plastic changes involved in learning and memory have been analyzed in detail in simple animals such as invertebrates and in circuits of mammalian brains mainly by intracellular recordings of neuronal activity. In the last decades, the evolution of techniques such as microelectrode arrays (MEAs) that allow simultaneous, long-lasting, noninvasive, extracellular recordings from a large number of neurons has proven very useful to study long-term processes in neuronal networksin vivoandin vitro. In this work, we start off by briefly reviewing the microelectrode array technology and the optimization of the coupling between neurons and microtransducers to detect subthreshold synaptic signals. Then, we report MEA studies of circuit formation and activity in invertebrate models such asLymnaea,Aplysia, andHelix. In the following sections, we analyze plasticity and connectivity in cultures of mammalian dissociated neurons, focusing on spontaneous activity and electrical stimulation. We conclude by discussing plasticity in closed-loop experiments.
Effect of TACI Signaling on Humoral Immunity and Autoimmune Diseases
Authors: Zhang Yi , Li Jun , Zhang Ya-Min , Zhang Xiao-Ming , Tao Juan
Published: March 2015

Transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI) is one of the receptors of B cell activating factor of the tumor necrosis factor family (BAFF) and a proliferation-inducing ligand (APRIL). TACI is a regulator in the immune responses. TACI inhibits B cell expansion and promotes the differentiation and survival of plasma cells. The mechanisms underlying these effects probably involve changed expressions of some crucial molecules, such as B lymphocyte induced maturation protein-1 (Blimp-1) and inducible T-cell costimulator ligand (ICOSL) in B cells and/or plasma cells. However, abnormal TACI signaling may relate to autoimmune disorders. Common variable immune deficiency (CVID) patients with heterozygous mutations inTACIalleles increase susceptibility to autoimmune diseases.Taci−/−mice and BAFF transgenic mice both develop signs of human SLE. These findings that indicate inappropriate levels of TACI signaling may disrupt immune system balance, thereby promoting the development of autoimmune diseases. In this review, we summarize the basic characteristics of the TACI ligands BAFF and APRIL, and detail the research findings on the role of TACI in humoral immunity. We also discuss the possible mechanisms underlying the susceptibility of CVID patients withTACImutations to autoimmune diseases and the role of TACI in the pathogenesis of SLE.
Characterization of the Fatty Acids Present in Wastewaters from Production of Biodiesel Tilapia
Authors: Braga Erika de A. S. , Malveira Jackson de Q. , Milhome Maria Aparecida L. , de Aquino Marisete D. , Nascimento Ronaldo F. do
Published: March 2015

Biodiesel obtained from oil extracted from the viscera of tilapia is a viable alternative in the replacement of petroleum fuels. However, during the purification step is performed biodiesel washing water is performed, which generates high effluent pollutant loads due to the reagents used and the very composition of the raw material. This study aims to characterize the fatty acids present in water from washing of the process of purifying biodiesel tilapia (Oreochromis niloticus). Fatty acid compositions were determined using gas chromatography (GC-FID). The results showed that the fatty acids present in greater quantities in the effluent were lauric (C12: 0), followed by myristic (C14: 0), palmitic (C16: 0), oleic (C18: 1), stearic (C18: 0), linolenic (C18: 3), and linoleic (C18: 2) acids. Therefore, the levels of oil and grease found in the rinse water from washing of the oil biodiesel tilapia are far above the allowed values above; thus they do not comply with Brazilian federal regulations.
Neuronal Nitric Oxide Synthase Is Dislocated in Type I Fibers of Myalgic Muscle but Can Recover with Physical Exercise Training
Authors: Jensen L. , Andersen L. L. , Schrøder H. D. , Frandsen U. , Sjøgaard G.
Published: March 2015

Trapezius myalgia is the most common type of chronic neck pain. While physical exercise reduces pain and improves muscle function, the underlying mechanisms remain unclear. Nitric oxide (NO) signaling is important in modulating cellular function, and a dysfunctional neuronal NO synthase (nNOS) may contribute to an ineffective muscle function. This study investigated nNOS expression and localization in chronically painful muscle. Forty-one women clinically diagnosed with trapezius myalgia (MYA) and 18 healthy controls (CON) were included in the case-control study. Subsequently, MYA were randomly assigned to either 10 weeks of specific strength training (SST,n=18), general fitness training (GFT,n=15), or health information (REF,n=8). Distribution of fiber type, cross-sectional area, and sarcolemmal nNOS expression did not differ between MYA and CON. However, MYA showed increased sarcoplasmic nNOS localization (18.8 ± 12 versus 12.8 ± 8%,P=0.049) compared with CON. SST resulted in a decrease of sarcoplasm-localized nNOS following training (before 18.1 ± 12 versus after 12.0 ± 12%;P=0,027). We demonstrate that myalgic muscle displays altered nNOS localization and that 10 weeks of strength training normalize these disruptions, which supports previous findings of impaired muscle oxygenation during work tasks and reduced pain following exercise.
Prediction of Cancer Proteins by Integrating Protein Interaction, Domain Frequency, and Domain Interaction Data Using Machine Learning Algorithms
Authors: Huang Chien-Hung , Peng Huai-Shun , Ng Ka-Lok
Published: March 2015

Many proteins are known to be associated with cancer diseases. It is quite often that their precise functional role in disease pathogenesis remains unclear. A strategy to gain a better understanding of the function of these proteins is to make use of a combination of different aspects of proteomics data types. In this study, we extended Aragues’s method by employing the protein-protein interaction (PPI) data, domain-domain interaction (DDI) data, weighted domain frequency score (DFS), and cancer linker degree (CLD) data to predict cancer proteins. Performances were benchmarked based on three kinds of experiments as follows: (I) using individual algorithm, (II) combining algorithms, and (III) combining the same classification types of algorithms. When compared with Aragues’s method, our proposed methods, that is, machine learning algorithm and voting with the majority, are significantly superior in all seven performance measures. We demonstrated the accuracy of the proposed method on two independent datasets. The best algorithm can achieve a hit ratio of 89.4% and 72.8% for lung cancer dataset and lung cancer microarray study, respectively. It is anticipated that the current research could help understand disease mechanisms and diagnosis.
Robust Design Optimization of a 4-UPS-S Parallel Manipulator for Orientation-Regulating Control System of Solar Gather Panels
Authors: Cui Guohua , Zhou Haidong , Zhang Haiqiang , Zhang Dan , Zhang Yanwei
Published: March 2015

This paper proposes a redundantly actuated parallel manipulator 4-UPS-S that is applicable for orientation adjustment in the gathering process of solar power. A thorough analysis involving the kinematic issues is performed. Inverse kinematic problems are solved in the close-loop. The Jacobian matrix and some performance indexes are analytically derived. The multiobjective optimization model is established, and the determinacy optimization is completed on the basis of previous research works. Six-Sigma robust analysis is performed on the basis of the determinacy optimal solution. Results show that 4-UPS-S does not satisfy the quality requirement. Therefore, it is necessary to implement Six-Sigma robust optimization, and select optimial solution of robustness to complete the nondeterminacy optimization. The research results show that the proposed methodology has a simple operation and high optimization efficiency. The methodology commodiously obtains robustness parallel manipulator that satisfies the quality requirement.
Sleep Duration and Sleep Quality following Acute Mild Traumatic Brain Injury: A Propensity Score Analysis
Authors: Huang Ting-Yun , Ma Hon-Ping , Tsai Shin-Han , Chiang Yung-Hsiao , Hu Chaur-Jong , Ou Juchi
Published: March 2015

Introduction. Mild traumatic brain injury (mTBI) has been widely studied and the effects of injury can be long term or even lifelong. This research aims to characterize the sleep problems of patients following acute mTBI.Methods. A total of 171 patients with mTBI within one month and 145 non-mTBI controls were recruited in this study. The questionnaire, Pittsburgh Sleep Quality Index (PSQI), was used to evaluate seven aspects of sleep problems. A propensity score method was used to generate a quasirandomized design to account for the background information, including gender, age, Beck’s Anxiety Index, Beck’s Depression Index, and Epworth Sleepiness Scale. The effect was evaluated via cumulative logit regression including propensity scores as a covariate.Results. Before adjustment, about 60% mTBI patients and over three quarters of control subjects had mild sleep disturbance while one third mTBI patients had moderate sleep disturbance. After adjusting by the propensity scores, the scores of sleep quality and duration were significant between mTBI and control groups.Conclusion. Our study supports that sleep problem is common in mTBI group. After adjusting the confounders by propensity score, sleep duration and subjective sleep quality are the most frequently reported problems in mTBI patients within one month after the injury.
Comparison of GnRH Agonist, GnRH Antagonist, and GnRH Antagonist Mild Protocol of Controlled Ovarian Hyperstimulation in Good Prognosis Patients
Authors: Stimpfel Martin , Vrtacnik-Bokal Eda , Pozlep Barbara , Virant-Klun Irma
Published: March 2015

The reports on how to stimulate the ovaries for oocyte retrieval in good prognosis patients are contradictory and often favor one type of controlled ovarian hyperstimulation (COH). For this reason, we retrospectively analyzed data from IVF/ICSI cycles carried out at our IVF Unit in good prognosis patients (aged <38 years, first and second attempts of IVF/ICSI, more than 3 oocytes retrieved) to elucidate which type of COH is optimal at our condition. The included patients were undergoing COH using GnRH agonist, GnRH antagonist or GnRH antagonist mild protocol in combination with gonadotrophins. We found significant differences in the average number of retrieved oocytes, immature oocytes, fertilized oocytes, embryos, transferred embryos, embryos frozen per cycle, and cycles with embryo freezing between studied COH protocols. Although there were no differences in live birth rate (LBR), miscarriages, and ectopic pregnancies between compared protocols, pregnancy rate was significantly higher in GnRH antagonist mild protocol in comparison with both GnRH antagonist and GnRH agonist protocols and cumulative LBR per cycle was significantly higher in GnRH antagonist mild protocol in comparison to GnRH agonist protocol. Our data show that GnRH antagonist mild protocol of COH could be the best method of choice in good prognosis patients.
Intracellular Oxidant Activity, Antioxidant Enzyme Defense System, and Cell Senescence in Fibroblasts with Trisomy 21
Authors: Rodríguez-Sureda Víctor , Vilches Ángel , Sánchez Olga , Audí Laura , Domínguez Carmen
Published: March 2015

Down’s syndrome (DS) is characterized by a complex phenotype associated with chronic oxidative stress and mitochondrial dysfunction. Overexpression of genes on chromosome-21 is thought to underlie the pathogenesis of the major phenotypic features of DS, such as premature aging. Using cultured fibroblasts with trisomy 21 (T21F), this study aimed to ascertain whether an imbalance exists in activities, mRNA, and protein expression of the antioxidant enzymes SOD1, SOD2, glutathione-peroxidase, and catalase during the cell replication processin vitro. T21F had high SOD1 expression and activity which led to an interenzymatic imbalance in the antioxidant defense system, accentuated with replicative senescence. Intracellular ROS production and oxidized protein levels were significantly higher in T21F compared with control cells; furthermore, a significant decline in intracellular ATP content was detected in T21F. Cell senescence was found to appear prematurely in DS cells as shown by SA-β-Gal assay and p21 assessment, though not apoptosis, as neither p53 nor the proapoptotic proteins cytochrome c and caspase 9 were altered in T21F. These novel findings would point to a deleterious role of oxidatively modified molecules in early cell senescence of T21F, thereby linking replicative and stress-induced senescence in cultured cells to premature aging in DS.
Imbalance of the Nerve Growth Factor and Its Precursor as a Potential Biomarker for Diabetic Retinopathy
Authors: Mysona B. A. , Matragoon S. , Stephens M. , Mohamed I. N. , Farooq A. , Bartasis M. L. , Fouda A. Y. , Shanab A. Y. , Espinosa-Heidmann D. G. , El-Remessy A. B.
Published: March 2015

Our previous studies have demonstrated that diabetes-induced oxidative stress alters homeostasis of retinal nerve growth factor (NGF) resulting in accumulation of its precursor, proNGF, at the expense of NGF which plays a critical role in preserving neuronal and retinal function. This imbalance coincided with retinal damage in experimental diabetes. Here we test the hypothesis that alteration of proNGF and NGF levels observed in retina and vitreous will be mirrored in serum of diabetic patients. Blood and vitreous samples were collected from patients (diabetic and nondiabetic) undergoing vitrectomy at Georgia Regents University under approved IRB. Levels of proNGF, NGF, andp75NTRshedding were detected using Western blot analysis. MMP-7 activity was also assayed. Diabetes-induced proNGF expression and impaired NGF expression were observed in vitreous and serum. Vitreous and sera from diabetic patients(n=11)showed significant 40.8-fold and 3.6-fold increases, respectively, compared to nondiabetics(n=9). In contrast, vitreous and sera from diabetic patients showed significant 44% and 64% reductions in NGF levels, respectively, compared to nondiabetics. ProNGF to NGF ratios showed significant correlation between vitreous and serum. Further characterization of diabetes-induced imbalance in the proNGF to NGF ratio will facilitate its utility as an early biomarker for diabetic complications.
Study of the Gastroprotective Effect of Extracts and Semipurified Fractions ofChresta martiiDC. and Identification of Its Principal Compounds
Authors: Franco E. S. , Mélo M. E. B. , Jatobá B. J. A. , Santana A. L. B. D. , Silva A. A. R. , Silva T. G. , Nascimento M. S. , Maia M. B. S.
Published: March 2015

Chresta martii(Asteraceae) is a species widely used by the population of the Xingu region of Sergipe, Brazil, in the form of a decoction (aerial parts) for the treatment of gastrointestinal diseases. The study aims to assess the gastroprotective activity of organic extracts and semipurified fractions and identify the principal compounds present inC. martiiresponsible for such activity. The organic extracts (cyclohexane: ECCm, ethyl acetate: EACm, and ethanol: EECm) were obtained from the dried aerial parts (500 g) ofC. martii. For evaluation of the gastroprotective activity of extracts (50, 100, or 200 mg/kg; p.o.), maleSwiss Webstermice (25–30 g) were used which had gastric ulcers induced by indomethacin (40 mg/kg, s.c.) or ethanol (0.2 mL/animal; p.o.). Among the extracts evaluated, EACm exhibited significant (P<0.05) gastroprotective activity in the models used. The fractionation of EACm was performed in a silica gel column 60 eluted with the following compounds: [chloroform—F1 yield (10%)], [chloroform/ethyl acetate (1/1)—F2 yield (6%)], [ethyl acetate—F3 yield (8%)], and [ethyl/methanol acetate (1/1)—F4 yield (5%)]. Of the fractions described above, the F1 (25 mg/kg; p.o.) had greater gastroprotective activity (P<0.05) than that displayed by ranitidine (80 mg/kg; p.o.) in the ethanol-induced ulcer model. The refractionation of F1 produced 23 subfractions and from these two yellow amorphous compounds were obtained by recrystallization, Rf: 0.46 and 0.31 (ethyl acetate : chloroform 5 : 5). The compounds isolated were characterized by nuclear magnetic resonance spectroscopy (1H-NMR and13C-NMR) and identified as flavones: chrysoeriol (yield: 0.43%) and 3′,4′-dimethoxyluteolin (yield: 0.58%).Conclusion. Flavone 3′,4′-dimethoxyluteolin is the principal compound present in the speciesC. martiiand is probably responsible for gastroprotective activity observed in this species.