bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability of a rectangular plate axially compressed on its two opposite free edges
Authors: Sharifian R. , Belubekyan V.
Published: April 2012

The stability of a rectangular plate under two different compressive loading scenarios applied to the free edges of the plate has been investigated. It is assumed that under the applied load the edges have translational and rotational degrees of freedom. In the first case, a conservative external force, that is assumed to have a fixed direction with respect to the deforming body, is applied while in the second case the load is directed to be tangential to the deflected middle surface, the follower force. It is found that for a sufficiently narrow plate the buckling is localized in the neighborhood of free edges as the conservative load is applied. A similar phenomenon is known for the case when a plate is uniformly compressed along hinged edges. In the case of a follower force, the static formulation of the problem leads to the conclusion that localized buckling does not exist. However, depending on the parameters of the problem, the usual (global) buckling is predicted.
Synthesis, Characterization and Properties of New Lauryl Amidopropyl Trimethyl Ammoniums
Authors: Liu Hongqin , Li Fei , Xu Baocai , Zhang Guiju , Han Fu , Zhou Yawen , Xin Xiulan , Xu Bo
Published: April 2012

A new lauryl amidopropyl trimethyl ammonium methyl carbonate with the formula CH3(CH2)10CONH(CH2)3N+(CH3)3CH3CO3− was synthesized via a high pressure process with tertiary amines and dimethyl carbonate, and its chemical structure was confirmed using 1H‐NMR spectra, mass spectral fragmentation, and FTIR spectroscopic analysis. In addition, several quaternary ammonium salts with new counterions X− (X−=HCO3−, HCOO−, CH3COO−, CH3CH(OH)COO−) were also synthesized by the ion exchange reaction of methyl carbonate quaternary ammoniums with corresponding acids. The surface activities of these compounds were measured, including surface tension (γ), critical micelle concentration and minimum surface area (Amin) at 25 °C. Adsorption and micellization free energies of these quaternary ammonium salts in their solutions showed a good tendency towards adsorption at interfaces. The antimicrobial activities are reported for the first time against representative bacteria and fungi for lauryl amidopropyl trimethyl ammoniums. It was found that the antimicrobial potency was Gram‐positive bacteria > fungi > Gram‐negative bacteria.
Plant Remains from the Laisong Formation of Manipur
Authors: Singh M. Chandra , Kushwaha R. A. S. , Srivastava Gaurav , Mehrotra R. C.
Published: April 2012

Some plant remains are described from the Laisong Formation (Barail Group) of Thoubal and Senapati districts of Manipur. The flora is diverse comprising gymnospermous, monocotyledonous and dicotyledonous forms and indicates tropical to subtropical climate in the vicinity of the area during the deposition of the host rocks.
Establishing a head and neck unit in a developing country
Authors: Aswani J , Baidoo K , Otiti J
Published: April 2012

Head and neck cancers pose an especially serious problem in developing countries due to late presentation requiring complex surgical intervention. These countries are faced with many challenges, ranging from insufficient health care staff to problems with peri-operative requirements, diagnostic facilities, chemoradiation services and research funding.

These challenges can be addressed through the training of head and neck surgeons and support personnel, the improvement of cancer awareness in local communities, and the establishment of dedicated head and neck institutes which focus on the special needs of head and neck cancer patients.

All these changes can best be achieved through collaborative efforts with external partners. The Karl Storz Fellowship in Advanced Head and Neck Cancer, enabling training at the University of Cape Town, South Africa, has served as a springboard towards establishing head and neck services in developing sub-Saharan African countries.
Complete response in a melanoma patient treated with imatinib
Authors: Brown M C , Casasola R J
Published: April 2012

Background:

Imatinib therapy has been successful in gastrointestinal stromal tumours containing mutation of the KIT gene. However, there are few reported cases of successful imatinib therapy in patients with melanoma containing KIT gene mutation or c-kit protein expression.

Methods and results:

A 52-year-old man developed metastatic melanoma from a primary melanoma in the left side of the nasopharynx. The tumour was positive for c-kit protein, and there was a KIT mutation in exon 11. He was treated with imatinib. A follow-up scan one year later showed a complete response. Treatment targeting the biological characteristics of melanoma proved successful in this patient.
Left-sided neck dissection and chylothorax: a rare complication and its management
Authors: Prabhu V , Passant C
Published: April 2012

Objective:

We present a case of bilateral chylothorax, a rare but life-threatening complication, which developed following a left-sided neck dissection.

Method:

Case report and literature review.

Results:

Chylous leakage fistula is a known complication following neck dissection and occurs in 1 to 2 per cent of patients. After left-sided neck dissection, chylothorax is uncommon and bilateral chylothorax is even rarer. Chylothorax is encountered following certain thoracic procedures, especially superior mediastinal dissection for thyroid cancer treatment. We discuss in detail the successful management of a complicated case.

Conclusion:

We discuss various management options for this condition, and we summarise its successful management within our department.
Theoretical analysis of the ICRH antenna's impedance matching for ELMy plasmas on EAST
Authors: DU DAN , GONG XUEYU , WANG ZHENHUA , YU JUN , ZHENG PINGWEI
Published: April 2012

A well-optimized design of an ion cyclotron resonance heating (ICRH) antenna is very important for steady-state plasma heating with high radio frequency (RF) power of several tens of megawatts. However, a sharp decrease in the coupling RF power because of impedance mismatch of ICRH system is an issue that must be resolved for present-day fusion reactors and International Thermonuclear Experimental Reactor. This paper has theoretically analyzed the ICRH antenna's impedance matching for ELMy plasmas on experimental advanced superconducting tokamak (EAST) by the transmission line theory. The results indicate that judicious choice of the optimal feeder location is found useful for adjustable capacitors' tolerance to the variations of the antenna input impedance during edge-localized mode (ELM) discharge, which is expected to be good for the design of ICRH antenna system and for real-time feedback control during ELM discharge on EAST.
Reproductive biology of the starfishPharia pyramidatus(Echinodermata: Asteroidea) from the Mexican tropical Pacific
Authors: Benítez-Villalobos Francisco , Martínez-García Maritza
Published: April 2012

The starfishPharia pyramidatusis a tropical species of high ecological importance, mainly because of its role as generalist predator. Nevertheless, there are no studies about its reproduction. This study analysed the reproductive biology ofP. pyramidatusbased on monthly time-series samples from April 2008 to March 2009 at Isla Montosa in the Mexican tropical Pacific. The gonad index (GI), and pyloric caecum index (PCI) were determined and the results were corroborated by histological examination of the gonads.Pharia pyramidatusis a gonochoric asteroid and the ratio of males to females was not significantly different throughout the year. Gametogenesis showed high synchrony among males and females and five stages were recognized for both sexes. Spawning occurred from July to September. Maximum oocyte size was ~150μm and mean fecundity was 7.3 ± 1.2 millions of oocytes per female. GI and PCI showed seasonal variations and an inverse relationship from May to August. Sea-bottom temperature and photoperiod showed a direct relationship with GI, and apparently constitute the proximate causes of the seasonal reproductive pattern observed inP. pyramidatus, while the highly seasonal rainfall and strong upwelling probably act as ultimate causes.
Does the invasion ofCaulerpa racemosavar.cylindraceaaffect the feeding habits of amphipods (Crustacea: Amphipoda)?
Authors: Vázquez-Luis Maite , Sanchez-Jerez Pablo , Bayle-Sempere Just T.
Published: April 2012

Ecological interactions involving introduced seaweeds constitute an important research gap, since they could alter the trophic dynamics of native populations, but indirect effects on trophic levels are poorly known. The seaweedCaulerpa racemosais one of the most notable invaders in the Mediterranean Sea. It is well known thatC. racemosamodifies the amphipod community with respect to native habitats, but nothing is known regarding the common use of the same trophic resources. Therefore, the aim of this study was to assess if the feeding habits of amphipods associated with algal habitats are affected by the spread of the invasiveC. racemosa, through stomach content analysis of amphipods living in both native and invaded seaweed assemblages. A total of 240 specimens of 14 species of amphipods were examined. Ten species were present in both studied habitats (native and invaded), while two were exclusive to native and invaded habitats, respectively. Ten individuals of each species at each habitat were selected and their gut contents were examined. A total of 11 different items was found in the gut contents: detritus; vegetal detritus; algae; animal tissue; Oligochaeta; Polychaeta; Foraminifera; Crustacea; Sipuncula; diatoms; and non-identified items. The expansion ofC. racemosainto the native algal community changes the feeding habits of herbivorous amphipods, since their preferred food (epiphytic algae) is not available in the new habitat produced byC. racemosa. This community change occurs because of the presence of caulerpenyne inC. racemosa, which retards the growth of epiphytic algae. Nevertheless, other species are not affected or benefited by the invasion, such as detritivorous species whose main food source and habitat remains available. Altogether, slight changes in the trophodynamism of amphipod assemblages have been detected, which are not seen as relevant in an initial stage. However, they might be promoting some indirect effects in the energetic budget of populations, which may affect the life history. Further studies on food-web interactions in the ecosystems affected by invasive species are necessary.
Amino acids in the octocoralVeretillum cynomorium: the effect of seasonality and differences from scleractinian hexacorals
Authors: Baptista Miguel , Maulvault Ana Luísa , Trübenbach Katja , Narciso Luis , Marques António , Rosa Rui
Published: April 2012

The majority of biochemical studies in corals has been focused on the lipidic composition and little attention has been given to the amino acid profile of these invertebrates. The objectives of this work were to investigate, for the first time, the temporal variations in the total amino acid (AA) composition of an octocoral, namely the sea penVeretillum cynomorium, and to evaluate possible interspecific differences in AA profile between this octocoral and hexacorals. The quantitatively most important AAs inV. cynomoriumcolonies were: glutamic acid, varying from 3.92 to 5.94% dry weight (dw) and representing around 14–15% of total AA content; aspartic acid (3.34–4.99% dw; 11–12%); and glycine (2.87–4.57% dw; 9–12%). On the other hand, the minor AAs were methionine (0.41–0.73% dw; 1–2%) and histidine (0.54–0.76% dw; 2%). Almost all AAs showed the same significant seasonal variations, with the highest values in February, second highest in October and the lowest in June. Some AAs, namely lysine, phenylalanine and methionine did not follow this trend and showed the major peak in October. Most of the AA variations seemed to be linked to changes in food availability and/or gametogenesis. Principal component analysis clearly separated the octocoral from the group of hexacorals, mainly due to the higher percentages of arginine, tyrosine and glycine inV. cynomorium, and valine, serine, histidine, isoleucine and alanine in hexacorallia species. We speculate that this differentiation possibly derived from physiological differences related to phylogeny, and was not affected by reproductive or environmental seasonality.
Morphometric variation in the shape of the cephalothorax of shrimpXiphopenaeus kroyerion the east coast of Brazil
Authors: Bissaro Fábio Guilherme , Gomes-Jr José Louvise , Di Beneditto Ana Paula Madeira
Published: April 2012

The objective of this study was to analyse the differences in shape of the cephalothorax in four fishery stocks of sea-bob shrimpXiphopenaeus kroyerithat are distributed on the east coast of Brazil, applying geometric morphometry as the analytical tool. Samples were collected at the fishing ports of Caravelas (17°43′S 39°15′W), Vitória (20°15′S 40°14′W), Atafona (21°35′S 41°01′W) and Farol de São Tomé (22°02′S 41°02′W), and variations in shape of the cephalothorax of the shrimps were evaluated by univariate and multivariate techniques. Analysis of variance followed by the Tukey test indicated that shrimps collected at the port of Farol de São Tomé were significantly smaller than the others, and size of individuals was inversely related to latitude. Discriminant analysis revealed the formation of two morphologically different groups between the areas of collection. Individuals collected in Caravelas, Vitória and Atafona, suffering permanent influence of freshwater discharge, associated with sandy–muddy substrate, constituted a different group compared to individuals collected in Farol de São Tomé, area without this kind of influence and with sandy substrate, where the average water temperature is lower and salinity is higher. Considering the commercial importance of the target species, the technique could be applied to its fisheries management. It allows the recognition of stocks and inference about the processes of fishing area occupation.
Severe infections caused bySalmonellaEnteritidis PT8/7 linked to a private barbecue
Authors: MERTENS E. , KREHER H. , RABSCH W. , BORNHOFEN B. , ALPERS K. , BURCKHARDT F.
Published: April 2012

A cohort study on a barbecue-associatedSalmonellaoutbreak was conducted to describe the burden of disease and to identify the outbreak vehicle. Dose–response relationships were tested with Fisher's exact and Wilcoxon rank sum tests (alpha = 0·05).S. Enteritidis isolates were cultured and phage-typed. Information was available for 11 out of 14 individuals attending the barbecue; all were healthy young adults (median age 27 years). The attack rate was 100%. Three cases were hospitalized and two developed acute pancreatitis. The exposure common to all cases was a vegetable pasta salad that had been stored unrefrigerated for 23 h. Consuming higher doses was associated with longer median symptom duration (7 daysvs. 4 days,P = 0·11).S. Enteritidis was found in the stools of nine barbecue guests. Phage type 8/7 was identified in the stools of the salad preparer and one barbecue guest. This outbreak shows thatS. Enteritidis can cause serious infection in young healthy individuals without well-known risk factors.
Numerical-asymptotic boundary integral methods in high-frequency acoustic scattering
Authors: Chandler-Wilde Simon N. , Graham Ivan G. , Langdon Stephen , Spence Euan A.
Published: April 2012

In this article we describe recent progress on the design, analysis and implementation of hybrid numerical-asymptotic boundary integral methods for boundary value problems for the Helmholtz equation that model time harmonic acoustic wave scattering in domains exterior to impenetrable obstacles. These hybrid methods combine conventional piecewise polynomial approximations with high-frequency asymptotics to build basis functions suitable for representing the oscillatory solutions. They have the potential to solve scattering problems accurately in a computation time that is (almost) independent of frequency and this has been realized for many model problems. The design and analysis of this class of methods requires new results on the analysis and numerical analysis of highly oscillatory boundary integral operators and on the high-frequency asymptotics of scattering problems. The implementation requires the development of appropriate quadrature rules for highly oscillatory integrals. This article contains a historical account of the development of this currently very active field, a detailed account of recent progress and, in addition, a number of original research results on the design, analysis and implementation of these methods.
A 120 GHz FMCW radar frontend demonstrator based on a SiGe chipset
Authors: Jahn Martin , Stelzer Andreas
Published: April 2012

This paper presents a frequency-modulated continuous-wave (FMCW) radar operating at 120 GHz, which features silicon–germanium (SiGe) chips that employ HBTs with 320 GHz fmax. The chipset comprises a fundamental-wave signal-generation chip with a voltage-controlled oscillator (VCO) that provides frequencies between 114 and 130 GHz and a corresponding dual–transceiver (TRX) chip that supports monostatic and quasi-monostatic radar configurations. The cascode amplifiers used in the TRX chip were characterized in separate test chips and yielded peak small-signal gains of approximately 15 dB. Finally, a quasi-monostatic two-channel FMCW radar frontend with on-board differential microstrip antennas was built on an RF substrate. FMCW radar measurements with frequency chirps from 116 to 123 GHz verified the functionality of the designed radar sensor.
Reducing Endorsement of Benevolent and Modern Sexist Beliefs
Authors: Becker Julia C. , Swim Janet K.
Published: April 2012

In two experiments, the present research identifies basic mechanisms for reducing endorsement of benevolent and modern sexist beliefs. Responses to attitudinal measures and a collective action measure on policy beliefs in Study 1 (N = 164) as well as to dating profiles in Study 1 and Study 2 (N = 159) support the hypothesis that endorsement of benevolent sexist beliefs can be reduced by providing information about its harmful consequences. Moreover, women and men become more aware of the full scope of gender discrimination and reduce their endorsement of modern sexist beliefs when they are provided with information about the harmful nature and pervasiveness of benevolent sexism. Theoretical implications regarding the linkage between benevolent and modern sexist beliefs and practical implications for reducing sexism are discussed.
Bearing Witness
Authors: Matheson Kimberly , Raspopow Katherine , Anisman Hymie
Published: April 2012

Recognizing discrimination does not necessarily translate into victim support. Willingness to provide support to a female victim of gender discrimination was hypothesized to vary as a function of whether the participant was male or female, along with the emotions conveyed by the victim (anger, shame, or no affect). Participants (N = 198) heard an audiotaped accounting of a woman’s discriminatory (vs. nondiscriminatory) conflict. When the victim encountered discrimination, males saw her as less blameworthy when she expressed anger, but their support was enhanced when she expressed shame. Females’ own anger predicted willingness to provide tangible support, although victim shame also elicited support. Thus, anger might motivate taking action, but its expression did not garner the support of others.
An intercomparison of temperature trends in the U.S. Historical Climatology Network and recent atmospheric reanalyses
Authors: Vose Russell S. , Applequist Scott , Menne Matthew J. , Williams Claude N. , Thorne Peter
Published: April 2012

Temperature trends over 1979–2008 in the U.S. Historical Climatology Network (HCN) are compared with those in six recent atmospheric reanalyses. For the conterminous United States, the trend in the adjusted HCN (0.327 °C dec−1) is generally comparable to the ensemble mean of the reanalyses (0.342 °C dec−1). It is also well within the range of the reanalysis trend estimates (0.280 to 0.437 °C dec−1). The bias adjustments play a critical role, as the raw HCN dataset displays substantially less warming than all of the reanalyses. HCN has slightly lower maximum and minimum temperature trends than those reanalyses with hourly temporal resolution, suggesting the HCN adjustments may not fully compensate for recent non‐climatic artifacts at some stations. Spatially, both the adjusted HCN and all of the reanalyses indicate widespread warming across the nation during the study period. Overall, the adjusted HCN is in broad agreement with the suite of reanalyses.
Allergen‐Induced Bone Marrow Eosinophilopoiesis and Airways Eosinophilic Inflammation in Leptin‐Deficient ob/ob Mice
Authors: Lintomen Leticia , Calixto Marina C. , Schenka André , Antunes Edson
Published: April 2012

Asthma and obesity are growing epidemics in the world. It is well established that obesity worsens the asthma outcomes. High‐fat diet‐induced obesity in mice exacerbates the pulmonary eosinophilic inflammation. We have used wild‐type (WT) and ob/ob mice to further explore the mechanisms by which obesity aggravates the pulmonary eosinophilic inflammation. The eosinophil (EO) number in bronchoalveolar lavage (BAL) fluid, lung tissue, blood, and bone marrow were evaluated at 24, 48, and 72 h after ovalbumin (OVA) challenge in sensitized mice. The basal EO number (phosphate‐buffered saline (PBS)‐instilled mice) in lung tissue was about 3.5‐fold greater in ob/ob compared with WT mice. OVA challenge in ob/ob mice promoted an EO accumulation into the lung that was accompanied by a lower emigration to airways lumen (BAL fluid) in comparison with WT mice. OVA challenge also markedly elevated the number of mature and immature EO in bone marrow of ob/ob mice at 24 h compared with WT group. Blood EO at 48 h was markedly greater in ob/ob mice. Tumor necrosis factor (TNF)‐α and interleukin (IL)‐10 levels in BAL fluid were significantly higher in ob/ob mice, whereas no changes for IL‐5 and eotaxin were found. The IL‐6 levels were significantly lower in ob/ob mice. In conclusion, OVA challenge in ob/ob obese mice potentiates eosinophilopoiesis and promotes an accumulation of EO into the lung tissue, delaying their transit to airways lumen. The longer EO remain into the lung tissue is likely to contribute, at least in part, to the asthma worsened by obesity.
Predictors of Attendance in a Practical Clinical Trial of Two Pediatric Weight Management Interventions
Authors: Jensen Chad D. , Aylward Brandon S. , Steele Ric G.
Published: April 2012

The objective of this study was to evaluate demographic and psychosocial predictors of attendance in a family‐based behavioral weight management clinical trial. Ninety‐three children and adolescents aged 7–17 (Mean age = 11.59, s.d. = 2.6) who were either overweight or obese (Mean BMI percentile = 98.2) and their parents received either a 10‐session behavioral treatment or a three‐session brief family intervention in the context of a randomized clinical trial (10). Psychosocial and anthropometric measures were obtained before enrollment and at the end of 10 weeks for both treatment groups. Univariate linear regression and hierarchical multiple regression analyses were used to identify predictors of attendance to treatment from an a priori set of hypothesized predictors. Three variables demonstrated significant associations with the dependent variable, percent of treatment sessions attended. Specifically, distance from participant's home to treatment site, lower gross family income, and youth self‐report of depressive symptoms were each associated with lower percent attendance (all Ps < 0.05). These results corroborate (i.e., income, depressive symptoms) and expand (i.e., distance from treatment site) previous reports in the literature of potential barriers to effective treatment for pediatric obesity, and suggest the need for research on treatment delivery methods that could increase participation among low‐income families (e.g., eHealth, mHealth options). Depressive symptoms could represent an additional barrier to treatment attendance, suggesting that assessment and treatment for these symptoms may be appropriate before commencing weight management treatment.
Replication fork dynamics and the DNA damage response
Authors: Jones Rebecca M. , Petermann Eva
Published: April 2012

Prevention and repair of DNA damage is essential for maintenance of genomic stability and cell survival. DNA replication during S-phase can be a source of DNA damage if endogenous or exogenous stresses impair the progression of replication forks. It has become increasingly clear that DNA-damage-response pathways do not only respond to the presence of damaged DNA, but also modulate DNA replication dynamics to prevent DNA damage formation during S-phase. Such observations may help explain the developmental defects or cancer predisposition caused by mutations in DNA-damage-response genes. The present review focuses on molecular mechanisms by which DNA-damage-response pathways control and promote replication dynamics in vertebrate cells. In particular, DNA damage pathways contribute to proper replication by regulating replication initiation, stabilizing transiently stalled forks, promoting replication restart and facilitating fork movement on difficult-to-replicate templates. If replication fork progression fails to be rescued, this may lead to DNA damage and genomic instability via nuclease processing of aberrant fork structures or incomplete sister chromatid separation during mitosis.
Structural insights into specificity and diversity in mechanisms of ubiquitin recognition by ubiquitin-binding domains
Authors: Searle Mark S. , Garner Thomas P. , Strachan Joanna , Long Jed , Adlington Jennifer , Cavey James R. , Shaw Barry , Layfield Robert
Published: April 2012

UBDs [Ub (ubiquitin)-binding domains], which are typically small protein motifs of <50 residues, are used by receptor proteins to transduce post-translational Ub modifications in a wide range of biological processes, including NF-κB (nuclear factor κB) signalling and proteasomal degradation pathways. More than 20 families of UBDs have now been characterized in structural detail and, although many recognize the canonical Ile44/Val70-binding patch on Ub, a smaller number have alternative Ub-recognition sites. The A20 Znf (A20-like zinc finger) of the ZNF216 protein is one of the latter and binds with high affinity to a polar site on Ub centred around Asp58/Gln62. ZNF216 shares some biological function with p62, with both linked to NF-κB signal activation and as shuttle proteins in proteasomal degradation pathways. The UBA domain (Ub-associated domain) of p62, although binding to Ub through the Ile44/Val70 patch, is unique in forming a stable dimer that negatively regulates Ub recognition. We show that the A20 Znf and UBA domain are able to form a ternary complex through independent interactions with a single Ub molecule, supporting functional models for Ub as a ‘hub’ for mediating multi-protein complex assembly and for enhancing signalling specificity.
DNA structure, nucleosome placement and chromatin remodelling: a perspective
Authors: Travers Andrew A. , Vaillant Cédric , Arneodo Alain , Muskhelishvili Georgi
Published: April 2012

A major question in chromatin biology is to what extent the sequence of DNA directly determines the genetic and chromatin organization of a eukaryotic genome? We consider two aspects to this question: the DNA sequence-specified positioning of nucleosomes and the determination of NDRs (nucleosome-depleted regions) or barriers. We argue that, in budding yeast, while DNA sequence-specified nucleosome positioning may contribute to positions flanking the regions lacking nucleosomes, DNA thermodynamic stability is a major component determinant of the genetic organization of this organism.
The ERMES complex and ER–mitochondria connections
Authors: Michel Agnès H. , Kornmann Benoît
Published: April 2012

Cellular organelles need to communicate in order to co-ordinate homoeostasis of the compartmentalized eukaryotic cell. Such communication involves the formation of membrane contact sites between adjacent organelles, allowing privileged exchange of metabolites and information. Using a synthetic protein designed to artificially tether the ER (endoplasmic reticulum) to mitochondria, we have discovered a yeast protein complex naturally involved in establishing and maintaining contact sites between these two organelles. This protein complex is physiologically involved in a plethora of mitochondrial processes, suggesting that ER–mitochondria connections play a central co-ordinating role in the regulation of mitochondrial biology. Recent biochemical characterization of this protein complex led to the discovery that GTPases of the Miro family are part of ER–mitochondria connections. The yeast Miro GTPase Gem1 localizes to ER–mitochondria interface and influences the size and distribution of mitochondria. Thus Miro GTPases may serve as regulators of the ER–mitochondria connection.
Dynamic clustering of IP3 receptors by IP3
Authors: Rahman Taufiq
Published: April 2012

The versatility of Ca2+ as an intracellular messenger stems largely from the impressive, but complex, spatiotemporal organization of the Ca2+ signals. For example, the latter when initiated by IP3 (inositol 1,4,5-trisphosphate) in many cells manifest hierarchical recruitment of elementary Ca2+ release events (‘blips’ and then ‘puffs’) en route to global regenerative Ca2+ waves as the cellular IP3 concentration rises. The spacing of IP3Rs (IP3 receptors) and their regulation by Ca2+ are key determinants of these spatially organized Ca2+ signals, but neither is adequately understood. IP3Rs have been proposed to be pre-assembled into clusters, but their composition, geometry and whether clustering affects IP3R behaviour are unknown. Using patch-clamp recording from the outer nuclear envelope of DT40 cells expressing rat IP3R1 or IP3R3, we have recently shown that low concentrations of IP3 cause IP3Rs to aggregate rapidly and reversibly into small clusters of approximately four IP3Rs. At resting cytosolic Ca2+ concentrations, clustered IP3Rs open independently, but with lower open probability, shorter open duration and lesser IP3-sensitivity than lone IP3Rs. This inhibitory influence of clustering on IP3R is reversed when the [Ca2+]i (cytosolic free Ca2+ concentration) increases. The gating of clustered IP3Rs exposed to increased [Ca2+]i is coupled: they are more likely to open and close together, and their simultaneous openings are prolonged. Dynamic clustering of IP3Rs by IP3 thus exposes them to local Ca2+ rises and increases their propensity for a CICR (Ca2+-induced Ca2+ rise), thereby facilitating hierarchical recruitment of the elementary events that underlie all IP3-evoked Ca2+ signals.
Differentiation of stages in joke comprehension: Evidence from an ERP study
Authors: Du Xue , Qin Yigui , Tu Shen , Yin Huazhan , Wang Ting , Yu Caiyun , Qiu Jiang
Published: April 2012

This study aimed to investigate the mechanisms underlying joke comprehension using event‐related potentials (ERPs). Fourteen healthy college students were presented with the context of a story without its joke or nonjoke ending, and then, when the story ending was presented, they were asked to make a funny/unfunny judgment about these endings. The behavioral results showed that there was no significant difference between funny and unfunny items, which meant that subjects could understand funny items as easily as unfunny ones. However, the ERP results showed that funny items initially elicited a more negative ERP deflection (N350–450) over frontocentral scalp regions. Dipole analysis localized the generators in the left temporal gyrus and the left medial frontal gyrus; it is suggested that these areas might be involved in detecting the incongruent element in joke comprehension. Between 600 and 800 ms, funny items subsequently elicited a more negative ERP deflection (N600–800) over frontocentral scalp regions and a more positive ERP deflection (P600–800) over posterior scalp regions. Dipole analysis localized the generator in the anterior cingulate cortex (ACC), an area involved in the breaking of mental set/expectation and the forming of novel associations. Finally, funny items elicited a more positive ERP deflection (P1250–1400) over anterior and posterior scalp regions. Dipole analysis localized the generators in the middle frontal gyrus and the fusiform gyrus, areas that might be related to the affective appreciation stage in joke process. Unlike that of Coulson and Kutas (2001), the present study might support the hypothesis of a three stage model of humor processing (humor detection, resolution of incongruity and humor appreciation).
Immunomodulation by human seminal plasma: a benefit for spermatozoon and pathogen?
Authors: Kelly R W , Critchley H O
Published: April 2012

The immunosuppressive effect of human seminal plasma and its implications for sperm survival are reviewed. Human semen contains high concentrations of prostaglandins that can effect a cytokine-mediated switch away from a cell-mediated immune response. This effect on antigen presenting cells would induce a state of non-responsiveness to sperm antigens in the female reproductive tract. It is postulated that the induction of anergy to sperm antigen may be fundamental to the continuing fecundity of the individual. However, although this immune system modulation will benefit the spermatozoa, the response to infective agents present in semen will also be affected, which may play a critical role in the aetiology and progress of sexually transmitted disease.
Estimating Legislators' Preferred Points
Authors: Londregan John
Published: April 2012

This paper shows that agnostic spatial models that simultaneously attempt to estimate legislators' preferred points and ideological locations for the proposals on which they vote, such as the well-known NOMINATE model of Poole and Rosenthal, are not identified. The problem arises because the agnostic estimators inherit the granularity of the voting data and, so, cannot recapture the underlying continuous parameter space. I propose an alternative estimator that achieves identification by modeling the agenda.
Testing for the Strong Form of Rational Expectations with Heterogeneously Informed Agents
Authors: Krause George A.
Published: April 2012

In recent years, political scientists have tested for the existence of rational expectations (RE) using survey-based aggregate data on subjective economic perceptions. These tests suffer from several conceptual shortcomings of a nontrivial nature. In this study, the meaning of RE is clarified, and also a test for strong rational expectations (SRE) where citizens possess heterogeneous information levels is set forth. These empirical tests provide insights into what kinds of information citizens use in forming expectations from that which they do not utilize but could employ to arrive at more accurate forecasts. Using inflation expectations data for the period January 1978—December 1993, the empirical findings indicate that citizens can benefit from greater reliance on objective economic and political conditions when formulating their inflation expectations. The broader implications of this work pertain not only to the execution of RE tests in political science, but also to distinguishing which types of information people do and do not (but could) incorporate in their decision-making calculus.
Cutpoint-Adjusted Interest Group Ratings
Authors: Herron Michael C.
Published: April 2012

While it is very common for Congressional researchers to use interest group ratings as measures of legislator policy preferences, this paper argues that the manner in which such ratings are calculated implies that they may poorly approximate the underlying legislator preferences on which they are based. In light of this, the paper develops a technique designed to adjust interest group ratings so that they more closely correlate with legislator preferences. It argues based on Monte Carlo simulations that the technique produces adjusted ratings that improve on unadjusted ratings, and it applies the adjustment technique to historical ratings published by the Americans for Democratic Action.
Modeling Duration Dependence
Authors: Zorn Christopher J. W.
Published: April 2012

As applications of duration analysis have burgeoned in political science, scholars have become increasingly aware of the potential substantive importance of duration dependence: the extent to which the conditional hazards of the events of interest are rising or falling over time. Here I discuss the issue of duration dependence, focusing on the distinction between “spurious” dependence due to unobserved heterogeneity and “true” duration dependence due to state dependence in the process of interest. I present a simple extension of a commonly used parametric duration model—the Weibull model—which allows researchers to assess the influence of causal variables on the nature and extent of duration dependence in their data. I then illustrate the application of this “generalized Weibull” model using data on the duration of international alliances.
Which Electoral Formula Is the Most Proportional? A New Look with New Evidence
Authors: Benoit Kenneth
Published: April 2012

A ranking exists in electoral systems research of different electoral formulas—the mathematical functions governing the conversion of votes into legislative seats—in terms of both proportionality of seats and votes and favorability to the largest party. I reexamine this issue with new methods and new evidence, attempting to cross-validate previous rankings using a larger and more controlled data set and more precise parametric methods than have been applied previously. The results by and large confirm previous knowledge but also illuminate several important new facets obscured in previous investigations. For example, at common ranges of district magnitude (from 5 to 15 seats), it is shown that electoral formula may matter at least as much as district magnitude in shaping proportionality.
A Further Look at Universalism and Partisanship in Congressional Roll Call Voting
Authors: Gaines Brian J. , Sala Brian R.
Published: April 2012

This note extends Melissa P. Collie's “Universalism and the Parties in the U.S. House of Representatives, 1921–80,” American Journal of Political Science 32, 4 (November 1988): 865–883. Detecting a strongly negative correlation between the time series of universalism and partisanship in roll call votes for the 67th through 96th U.S. Houses, Collie concluded that consensus and partisanship are alternative, rival means of organizing legislative activity. If robust, this finding ought not to be time- or chamber-specific: it should be in evidence over the whole (partisan) histories of both House and Senate, session by session. Moreover, the inverse relationship should persist under alternative operationalizations of both partisanship and universalism. Using several measures of partisanship and universalism, mostly based on roll call votes tabulated for sessions of Congress, we reassess this relationship for the 43rd through 105th Congresses. Collie's core finding persists for both chambers over the longer time span provided that one uses her measures. But results are weaker when sessions of Congress rather than Congresses are used as units of observation, and alternative operationalizations of partisanship and universalism do not strongly replicate the original finding.
Empirically Discriminating between Chaotic and Stochastic Time Series
Authors: Williams John T. , Huckfeldt Robert
Published: April 2012

In recent years, more and more social scientists have begun to view the world as inherently probabilistic (Suppes 1984; Gigerenzer 1987). Without detailing the philosophical underpinnings of such a view, this subtle movement away from deterministic positivism has been fed, in large part, by a recognition of the indeterminacy of strategic interaction among individuals and the inevitability of uncertainty in social relations (Boudon 1986). Chaos theory provides an alternative viewpoint from which to view indeterminacy because the complexity we see in the real world may, in theory, be a reflection of chaotic dynamics resulting from simple deterministic structures (Huckfeldt 1990). Particularly when processes are generated by social or strategic interaction among actors, nonlinear models provide useful representations and chaotic outcomes become conceivable. In short, the existence of a complex social reality is in itself inadequate evidence of indeterminacy.
Structuralism's Unpaid Epistemological Debts
Authors: HALE BOB
Published: April 2012

One kind of structuralism holds that mathematics is about structures, conceived as a type of abstract entity. Another denies that it is about any distinctively mathematical entities at all—even abstract structures; rather it gives purely general information about what holds of any collection of entities conforming to the axioms of the theory. Of these, pure structuralism is most plausibly taken to enjoy significant advantages over platonism. But in what appears to be its most plausible—modalised—version, even restricted to elementary arithmetic, it requires defence of a very strong possibility claim: that there could be a completed w-sequence of concrete objects. There are very serious epistemological difficulties in the way of providing the requisite defence.
Structure in Mathematics
Authors: MAC LANE SAUNDERS
Published: April 2012

The article considers structuralism as a philosophy of mathematics, as based on the commonly accepted explicit mathematical concept of a structure. Such a structure consists of a set with specified functions and relations satisfying specified axioms, which describe the type of the structure. Examples of such structures such as groups and spaces, are described. The viewpoint is now dominant in organizing much of mathematics, but does not cover all mathematics, in particular most applications. It does not explain why certain structures are dominant, not why the same mathematical structure can have so many different and protean realizations. ‘structure’ is just one part of the full situation, which must somehow connect the ideal structures with their varied examples.
Dietary Outcomes of the Healthy Dads Healthy Kids Randomised Controlled Trial
Authors: Burrows Tracy , Morgan Philip J. , Lubans David R. , Callister Robin , Okely Tony , Bray James , Collins Clare E.
Published: April 2012

Fathers have not been exclusively targeted in family‐based lifestyle programmes. The aim was to determine whether dietary intakes of fathers and children can be improved, following an intervention targeting fathers. Overweight and obese fathers (n = 50, 21–65 years, body mass index [mean ± standard deviation] 33.3 ± 4.1) and their children (5–12 years) were recruited. Dietary intake was assessed at baseline and 6 months (n = 35) by food frequency questionnaire. Linear mixed models determined differences by time. Fathers significantly reduced portion size (P = 0.03) but not energy intakes, whereas children reduced energy intakes (kJ) (P = 0.02). There is an opportunity to target fathers as to improve child intakes.
Developmental Assessment of Infants With Biliary Atresia
Authors: Caudle Susan E. , Katzenstein Jennifer M. , Karpen Saul , McLin Valérie
Published: April 2012

Objective:

The aim of the present study was to investigate whether male and female infants with biliary atresia (BA) differ cognitively and to confirm previously documented developmental lags in infants with BA before liver transplantation.

Methods:

With the Mullen Scales of Early Learning, we examined 21 female and 12 male infants (ages 3–20 months) with BA, comparing scores across indices by sex and correlating Mullen Scales of Early Learning scores with standard clinical and biochemical parameters.

Results:

Overall, both boys and girls were found to be vulnerable to developmental lags in the areas of expressive language (EL) and gross motor skills. In comparison with their male peers, girls were found to be weaker in the area of visual reception skills (P = 0.05) with a trend found for EL (P = 0.08). Girls were also found to have higher C‐bilirubin levels and to be of shorter length. Growth parameters were found to be correlated with EL scores. International normalized ratio was found to be correlated with gross motor performance and with a trend also noted for fine motor skills. Age at Kasai predicted receptive language skills.

Conclusions:

As has been shown, infants with BA appear to be vulnerable to developmental lags before transplantation. In particular, female infants appear to be vulnerable to cognitive and skill delays in comparison with their male peers. C‐bilirubin levels may play a role in this increased vulnerability for females.
Assessment of Control Tissue for Gene and Protein Expression Studies: A Comparison of Three Alternative Lung Sources
Authors: Passmore Margaret R. , Nataatmadja Maria , Fraser John F.
Published: April 2012

The use of an appropriate control group in human research is essential in investigating the level of a pathological disorder. This study aimed to compare three alternative sources of control lung tissue and to determine their suitability for gene and protein expression studies. Gene and protein expression levels of the vascular endothelial growth factor (VEGF) and gelatinase families and their receptors were measured using real-time reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The gene expression levels of VEGFA, placental growth factor (PGF), and their receptors, fms-related tyrosine kinase 1 (FLT1), and kinase insert domain receptor (KDR) as well as matrix metalloproteinase-2 (MMP-2) and the inhibitors, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-2 were significantly higher in lung cancer resections. The gene expression level of MMP-9 was significantly lower in the corresponding samples. Altered protein expression was also detected, depending on the area assessed. The results of this study show that none of the three control groups studied are completely suitable for gene and protein studies associated with the VEGF and gelatinase families, highlighting the need for researchers to be selective in which controls they opt for.
Stress Studies of Tenofovir Disoproxil Fumarate by HPTLC in Bulk Drug and Pharmaceutical Formulation
Authors: Havele Shweta , Dhaneshwar Sunil R.
Published: April 2012

A stability-indicating high-performance thin-layer chromatographic (HPTLC) method for determination of tenofovir disoproxil fumarate in bulk drug and in tablet has been developed and validated. The mobile phase selected was chloroform : methanol (9.0 : 1.0, v/v) with ultraviolet (UV) detection at 260 nm. The retention factor was found to be 0.49 ± 0.03 with correlation coefficients of 0.9994 in the range 300–1500 ng/spot and with an accuracy of 99.25%. Method had the potential to determine tenofovir disoproxil fumarate from tablet without any interference, and it was a stability-indicating one.