bluuebunny/crossref_metadata_2025 huggingface dataset:
Obstructive Sleep Apnea and Primary Snoring in Children With Epilepsy
Authors: Jain Sejal V. , Horn Paul S. , Simakajornboon Narong , Glauser Tracy A.
Published: May 2012

Sleep-related breathing disruptions in children with epilepsy are common and can range from primary snoring to obstructive sleep apnea. Untreated obstructive sleep apnea can lead to significant morbidity. This study aimed to identify factors associated with its occurrence and severity in children with epilepsy. Children with epilepsy and sleep disruption were evaluated with polysomnography and diagnosed with obstructive sleep apnea or primary snoring. Statistical analyses were done to identify differences within both the groups and among the subjects in the obstructive sleep apnea group. Uncontrolled epilepsy was a risk factor for obstructive sleep apnea (80%) compared with primary snoring (47%, P = .02). Obstructive index increased with increasing number of antiepileptic drugs. In children with epilepsy and disturbed sleep, obstructive sleep apnea is associated with uncontrolled epilepsy and is more severe with polytherapy use. Children with uncontrolled seizures on antiepileptic polytherapy should be routinely screened for obstructive sleep apnea.
Unimanual and Bimanual Intensive Training in Children With Hemiplegic Cerebral Palsy and Persistence in Time of Hand Function Improvement
Authors: Fedrizzi Ermellina , Rosa-Rizzotto Melissa , Turconi Anna Carla , Pagliano Emanuela , Fazzi Elisa , Pozza Laura Visonà Dalla , Facchin Paola ,   GIPCI Study Group
Published: May 2012

This study aims to compare in hemiplegic children the effectiveness of intensive training (unimanual and bimanual) versus standard treatment in improving hand function, assessing the persistence after 6 months. A multicenter, prospective, cluster-randomized controlled clinical trial was designed comparing 2 groups of children with hemiplegic cerebral palsy, treated for 10 weeks (3 h/d 7 d/wk; first with unimanual constraint-induced movement therapy, second with intensive bimanual training) with a standard treatment group. Children were assessed before and after treatment and at 3 and 6 months postintervention using Quality of Upper Extremity Skills Test (QUEST) and Besta Scales. One hundred five children were recruited (39 constraint-induced movement therapy, 33 intensive bimanual training, 33 standard treatment). Constraint-induced movement therapy and intensive bimanual training groups had significantly improved hand function, showing constant increase in time. Grasp improved immediately and significantly with constraint-induced movement therapy, and with bimanual training grasp improved gradually, reaching the same result. In both, spontaneous hand use increased in long-term assessment.
Black Supporters of Racial Profiling
Authors: Gabbidon Shaun L. , Higgins George E. , Wilder-Bonner Kideste M.
Published: May 2012

As an anomaly of extant literature that maintains Blacks as a collective are less supportive of racial profiling than other ethnic groups, this article explores the backgrounds of Blacks who support the practice of racial profiling (referred to as Black Supporters). This study analyzed a national Gallup poll that included measures on profiling and had a significant number of Black respondents ( N = 534). Black Supporters tended to be female; live in the Southern United States; and be politically conservative. Although multivariate analyses revealed few differences between Black Supporters and nonsupporters, the study represents an earnest attempt to explore Black support for a policing strategy that has both historically and contemporarily had negative effects on Black communities. We conclude the article by discussing the benefits of studying Black Supporters.
Laser processing of continuous carbon fibre reinforced polyphenylene sulphide organic sheets—Correlation of process parameters and reduction in static tensile strength properties
Authors: Jaeschke Peter , Kern Manuel , Stute Uwe , Kracht Dietmar , Haferkamp Heinz
Published: May 2012

In this article, the impact of laser-induced thermal damage on the static strength properties of consolidated continuous carbon fibre reinforced thermoplastics induced by high-power laser cutting is presented. Organic sheets based on a polyphenylene sulphide matrix are machined using a fibre laser providing a maximum output power of 6000 W. In this context, the influence of the applied laser power and the feed rate on the cut quality as well as the resulting tensile strength is discussed. In order to analyse the laser cutting edge through a quantitative evaluation of the damaged areas due to laser impact, optical micrographs are prepared. The results of tensile strength tests are compared with those measured from the specimens that were generated by a conventional processing technique (milling). A linear dependency between a specific part of the heat-influenced zone and the corresponding maximum tensile load is found. A reduced load bearing area, as a consequence of a modified fibre–matrix-structure due to laser impact, is identified as the responsible factor for reduced tensile strengths, especially for low feed rates.
School Improvement Networks as a Strategy for Large-Scale Education Reform
Authors: Glazer Joshua L. , Peurach Donald J.
Published: May 2012

The development and scale-up of school improvement networks is among the most important educational innovations of the last decade, and current federal, state, and district efforts attempt to use school improvement networks as a mechanism for supporting large-scale change. The potential of improvement networks, however, rests on the extent to which they can thrive in the turbulent world of U.S. education. In this article, we adapt a model of innovation scale-up and apply it to the problem of scaling-up educational networks. The framework identifies the constituent components of networks and environments, and the relationship between them. We demonstrate the framework’s utility by illustrating the relationship between two prominent educational networks –the Success for All Foundation and America’s Choice– and the educational environments in which they operated at two different points in time. Results suggest that without robust environmental support, networks are prone to a high degree of uncertainty and unpredictability.
The role of mechanisms, integration, and unification in science and psychology
Authors: Trafimow David
Published: May 2012

I assume the importance of unifying theories in science but suggest that psychologists do not understand the concept. To clarify, I distinguish unification from both mechanisms and from integration. The psychology literature is replete with mechanisms and also integration, but there is insufficient unification. Finally, I use potential performance theory as an example of unification in a small way in psychology. Given that this theory provides small-scale unification, there is reason to hope for large-scale unification in the future—a goal to which psychologists can and should aspire.
Duloxetine in Adults With ADHD
Authors: Bilodeau Mathieu , Simon Tarek , Beauchamp Miriam H. , Lespérance Paul , Dubreucq Simon , Dorée Jean-Pierre , Tourjman Smadar Valérie
Published: May 2012

Objective: To assess the effect of duloxetine on ADHD in adults. Method: In a 6-week double-blind trial, 30 adults with ADHD received placebo or duloxetine 60 mg daily. The Conners’ Adult ADHD Rating Scale (CAARS) and the Clinical Global Impression Scales (CGI) were used to assess symptom severity and clinical improvement. The Hamilton Anxiety Rating Scale (HARS) and the Hamilton Depression Rating Scale (HDRS) were used to measure the effect on anxiety and depressive symptoms. Results: The Duloxetine group showed lower score on CGI-Severity at Week 6 (3.00 vs. 4.07 for placebo, p < .001), greater improvement on CGI-Improvement (2.89 vs. 4.00 at Week 6, p < .001), and greater decreases on five of eight subscales of the CAARS. There was no treatment group effect on HDRS or HARS scores. Conclusion: Duloxetine may be a therapeutic option for adults with ADHD, but further studies are required to replicate these findings in larger samples.
Severity of Symptoms and Quality of Life in Medical Students With ADHD
Authors: O’Callaghan Pamela , Sharma Davendranand
Published: May 2012

Objective: In this study, the authors examined the severity of ADHD symptoms and related quality of life in 1st and 2nd year medical students diagnosed with ADHD. Method: The sample consists of 33 preclinical medical students previously diagnosed with ADHD. The Adult ADHD Quality of Life Scale (AAQoL) and Adult ADHD Self-Reported Checklist were administered. Results: Participants’ ADHD-related quality of life and life productivity were negatively correlated with the severity of their ADHD symptoms. Students receiving academic accommodations reported significantly higher ADHD symptoms. The presence of a comorbid condition contributed to significantly lower psychological health scores. Unexpectedly, women had significantly lower quality of life (AAQoL total score) and significantly lower psychological health scores than men. Conclusion: Since the majority of the sample reported severe ADHD symptoms while receiving medication treatment, the authors have concluded that it is important to develop psychosocial treatments to manage the associated distress from residual symptoms in medical students with ADHD.
Meeting recipients’ needs in dyadic cross-group helping: When the nature of the helper’s motivation matters
Authors: Siem Birte , Stürmer Stefan
Published: May 2012

This report introduces a series of hypotheses on how intergroup (dis)similarities between the helper’s and the recipient’s group may affect the recipient’s perceptions of the helper’s need-responsiveness. Hypotheses were tested in a real world context of helping (intercultural volunteerism) by using data from two discrete samples of interacting participants. As hypothesized, among culturally similar helper-recipient dyads (but not among dissimilar dyads) feelings of other-focused empathy increased the helper’s perceived responsiveness to the recipient’s needs, whereas among culturally dissimilar dyads (but not among similar dyads) ego-focused concerns decreased the helper’s need-responsiveness. In addition, among culturally dissimilar dyads helper’s need-responsiveness was more strongly contingent upon whether he or she found the recipient attractive or not than among culturally similar dyads. These findings suggest that members of out-groups who may require need-sensitive help most (members of dissimilar out-groups perceived as unattractive) may have a significantly reduced chance to receive it.
Texting, techspeak, and tweens: The relationship between text messaging and English grammar skills
Authors: Cingel Drew P. , Sundar S. Shyam
Published: May 2012

The perpetual use of mobile devices by adolescents has fueled a culture of text messaging, with abbreviations and grammatical shortcuts, thus raising the following question in the minds of parents and teachers: Does increased use of text messaging engender greater reliance on such ‘textual adaptations’ to the point of altering one’s sense of written grammar? A survey ( N = 228) was conducted to test the association between text message usage of sixth, seventh and eighth grade students and their scores on an offline, age-appropriate grammar assessment test. Results show broad support for a general negative relationship between the use of techspeak in text messages and scores on a grammar assessment, with implications for Social Cognitive Theory and Low-Road/High-Road Theory of Transfer of Learning. These results indicate that adolescents may learn through observation in communication technologies, and that these learned adaptations may be transferred to standard English through Low-Road transfer of learning. Further mediation analyses suggest that not all forms of textual adaptation are related to grammar assessment score in the same way. ‘Word adaptations’ were found to be negatively related to grammar scores, while ‘structural adaptations’ were found to be non-significant.
Fuel consumption evaluation of an optimized new hybrid pneumatic–combustion vehicle engine on several driving cycles
Authors: Basbous Tammam , Younes Rafic , Ilinca Adrian , Perron Jean
Published: May 2012

In this paper, we describe an optimization followed by a fuel-saving evaluation of a new concept of a hybrid pneumatic–combustion engine that can be obtained by modifying a conventional internal combustion engine without developing a new cylinder head. Until now, most studies on the pneumatic hybridization of internal combustion engines have dealt with a two-stroke pure pneumatic mode. The few concept studies that have dealt with a hybrid pneumatic–combustion four-stroke mode required a supplementary valve to be added to charge compressed air in the combustion chamber. This heavy modification cannot be carried out by simply adjusting an existing internal combustion engine because a new cylinder head should be developed. It is therefore not logical to suggest this concept as an option in vehicle powertrains to reduce fuel consumption. Moreover, those studies focus on spark-ignition engines; there are reasons to think that their concepts might not work adequately for diesel engines. Our concept is capable of making a diesel engine operate under two-stroke pneumatic motor modes, two-stroke pneumatic pump modes and four-stroke hybrid modes, without requiring an additional valve in the combustion chamber. This fact constitutes our study’s strength and innovation. The evaluation of our concept is based on ideal thermodynamic cycle modeling. The optimized valve actuation timings for all modes lead to generic maps that are independent of the engine size. The fuel economy is calculated based on the new European driving cycle and on the assessment and reliability of transport emission models and inventory system urban and rural cycles.
A ‘balikbayan’ in the field: scaling and (re)producing insider’s identity in a Philippine fishing community
Authors: Turgo Nelson Nava
Published: May 2012

Insider researchers are often construed as having an easy time in the field, with their stay in fieldwork sites less demanding than their outsider counterparts. In some ways, this is true, with less efforts to know the place, its people and history, and master the idioms of everyday life. But being an insider researcher could prove challenging in a place that ascribes a particular salience to a specific identity like ‘balikbayan’, a Filipino word for a native who has either lived or worked abroad for a number of years and returns home for a visit. Based on an empirical ethnographic study of a fishing community in the Philippines, I argue that insider researchers in developing economies like the Philippines are faced with more challenges pertaining to their newly acquired status identity as returning natives in the context of their ability to be mobile and jump scales – from local to national and global – and the economic and symbolic appurtenances, among many, attached to it. Thus, in the context of their status identity, insider researchers’ social reproduction in the field must be attended to in order to further understand the ways in which informants make sense of their place in the world and agency over the conduct of and their involvement in research of homecoming native researchers.
Clinical–Pathological Characterization of Diabetic Foot Infections
Authors: Aragón-Sánchez Javier
Published: May 2012

The present study has 3 aims: ( a) to characterize the clinical and pathological features of diabetic foot infections, ( b) to show the range of clinical presentations of moderate infections, and ( c) to analyze the different behavior of diabetic foot osteomyelitis regarding to its clinical presentation. A definitive diagnosis of the type of infection was made based on intraoperative findings and histopathology. Diabetic foot infections were classified into 2 types: soft tissue and bone infections. Mild infections were always superficial. Severe infections included 75% of necrotizing soft tissue infections. Moderate infections showed ample range of clinical presentations. Eighty-one patients presented osteomyelitis. Osteomyelitis was further classified as follows: osteomyelitis without ischemia and without soft tissue involvement (class 1), osteomyelitis with ischemia without soft tissue involvement (class 2), osteomyelitis with soft tissue involvement (class 3), and osteomyelitis with ischemia and soft tissue involvement (class 4). Forty-eight patients (59.3%) with osteomyelitis underwent conservative surgery, 32 (39.5%) had minor amputations including 9 open transmetatarsal amputations, and there was 1 (1.2%) major amputation. The characterization of osteomyelitis into 4 classes showed a statistically significant trend toward increased severity and increased amputation rate and mortality. In conclusion, the clinical presentation of foot infections in diabetic patients is very heterogeneous and can be classified into soft tissue infections (cellulitis, superficial and deep abscesses, and necrotizing soft tissue infections) and osteomyelitis, which was the most frequent type of infection found in the author’s series. Their division into 4 classes showed a statistically significant trend toward increased severity, amputation rate, and mortality. The diagnosis of deep soft tissue infections associated with osteomyelitis may be difficult to achieve before surgery.
Observations on J. C. Loudon’s beau ideal town of 1829
Authors: Johnson Donald Leslie
Published: May 2012

In 1829, the perceptive landscape gardener John Claudius Loudon published an essay in which he introduced the design of a “systematic plan” for the layout of an ideal London that became a theoretical model. Little known today, yet the influence of the Scot’s “beau ideal” is measurable on the course of town planning theory and practice for the remainder of the nineteenth century. This includes colonial Adelaide’s renowned park lands that were conceived in 1835 and executed in 1837.
Evaluating Quantitative and Qualitative Types of Change
Authors: Mencl Jennifer , Tay Louis , Schwoerer Catherine E. , Drasgow Fritz
Published: May 2012

In this research, the authors present theoretical explanations for quantitative and qualitative types of changes to evaluate the malleability of general self-efficacy (GSE) and specific self-efficacy (SSE) measures due to domain-specific training. First, the authors hypothesize that the change in the GSE measure due to sales training is a quantitative mean-difference (alpha) change. Second, they hypothesize that the change in SSE due to sales training is a qualitative (beta or gamma) change. Results of latent variable cross-lagged analysis on sales trainee data ( N = 417) support the authors’ hypothesis that the difference in GSE was quantitative. Findings also provide partial support of the second hypothesis that a change in a SSE measure was qualitative. The qualitative change is attributed to the novelty and complexity of the particular SSE tasks (i.e., direct selling). Additional analysis of rank-order consistency further validates the measures and demonstrates the GSE measure was consistent before and after training whereas the SSE scales were not as consistent. Theoretical and practical implications of the findings are discussed.
The Relationship between Transformational Leadership and Organizational Commitment
Authors: Khasawneh Samer , Omari Aieman , Abu-Tineh Abdullah M.
Published: May 2012

The purpose of this article is to determine the relationship between transformational leadership of vocational school principals on vocational teachers’ organizational commitment. A random sample of 340 vocational teachers responded to a three-part instrument (the transformational leadership questionnaire, the organizational commitment questionnaire and a demographic section). Means, standard deviations, Pearson correlations and stepwise regression analysis were used to analyse the data. The findings indicated that a strong, positive and significant relationship exists between transformational leadership (overall) and the organizational commitment dimension. Furthermore, the relationship between each component of transformational leadership and organizational commitment was found to be moderate, positive and significant. Finally, it is suggested that more workshops and training courses in transformational leadership should be sponsored by the Ministry of Education in Jordan to promote organizational commitment among vocational teachers.
Characterization of TLR4-mediated auto-antibody production in a mouse model of histidyl-tRNA synthetase-induced myositis
Authors: Harlow Lisa , Fernandez Irina , Soejima Makoto , Ridgway William M , Ascherman Dana P
Published: May 2012

We have previously shown that intramuscular immunization with a recombinant fragment of murine histidyl-tRNA synthetase (HRS) in the absence of exogenous adjuvant generates Ag-specific, IgG class switched Abs a murine model of myositis. Markedly diminished IgG anti-HRS auto-Ab responses in TLR4 signaling-deficient C3H/HeJ mice indicate that TLR4 is required for auto-Ab formation and/or class switching in this system. Comparative time course assessment of HRS-immunized C3H/HeOuJ (wild type) and C3H/HeJ (TLR4 mutant) mice shows here that despite significant impairment of class switched IgG anti-HRS responses in TLR4-deficient C3H/HeJ mice, production of IgM anti-HRS auto-Abs is relatively preserved—suggesting that TLR4-mediated signals modulate IgG class switching rather than auto-Ab formation in this genetic background. In C57BL/6-derived knockout mice lacking either MyD88 (B6.MyD88−/−) or TRIF (B6.TRIF−/−) adaptor molecules, immunization studies indicate that TRIF exerts a dominant role in the generation of HRS-specific IgG auto-Abs. Complementing these analyses, in vitro stimulation of unfractionated, as well as T cell-depleted, C3H/HeOuJ splenocytes with recombinant murine HRS reveals that TLR4-mediated generation of class switched auto-Abs can occur independently of T cell help. Overall, these findings support a broader role for TLR4 in the breakdown of immune tolerance and development of autoimmunity.
Targeting antiapoptotic A1/Bfl-1 by in vivo RNAi reveals multiple roles in leukocyte development in mice
Authors: Ottina Eleonora , Grespi Francesca , Tischner Denise , Soratroi Claudia , Geley Stephan , Ploner Andreas , Reichardt Holger M. , Villunger Andreas , Herold Marco J.
Published: May 2012

Gene-targeting studies in mice have identified the essential roles of most prosurvival Bcl-2 family members in normal physiology and under conditions of stress. The function of one member, Bcl2a1/Bfl-1/A1, is only poorly understood because of quadruplication of its gene locus in mice, hindering conventional knockout studies. To overcome this problem, we generated mouse models allowing traceable constitutive or reversible ablation of A1 in the hematopoietic system by RNA interference. Knockdown of A1 impaired early stages of T-cell differentiation, B-cell homeostasis, and sensitized transitional as well as follicular B cells to apoptosis induced by ligation of the B-cell receptor. As a consequence, B-cell proliferation in response to mitogens was severely impaired, whereas that of T cells appeared unaffected. Furthermore, depending on the extent of A1 knockdown, granulocytes showed increased spontaneous death in culture or failed to accumulate in significant numbers in vivo. These models highlight the critical role of A1 in leukocyte development and homeostasis, constituting valuable tools for investigating presumed roles of this Bcl-2 family member in immunity, tumorigenesis, and drug resistance.
Inherited thrombophilia in children with venous thromboembolism and the familial risk of thromboembolism: an observational study
Authors: Holzhauer Susanne , Goldenberg Neil A. , Junker Ralf , Heller Christine , Stoll Monika , Manner Daniela , Mesters Rolf , Krümpel Anne , Stach Michael , Nowak-Göttl Ulrike
Published: May 2012

Screening for inherited thrombophilia (IT) is controversial; persons at high risk for venous thromboembolism (VTE) who benefit from screening need to be identified. We tested 533 first- and second-degree relatives of 206 pediatric VTE patients for IT (antithrombin, protein C, protein S, factor V G1691A, factor II G20210A) and determined the incidence of symptomatic VTE relative to their IT status. The risk for VTE was significantly increased among family members with, versus without, IT (hazard ratio = 7.6; 95% confidence interval [CI], 4.0-14.5; P < .001) and highest among carriers of antithrombin, protein C, or protein S deficiency (hazard ratio = 25.7; 95% CI, 12.2-54.2; P < .001). Annual incidences of VTE were 2.82% (95% CI, 1.63%-4.80%) among family members found to be carriers of antithrombin, protein C, or protein S deficiency, 0.42% (0.12%-0.53%) for factor II G202010A, 0.25% (0.12%-0.53%) for factor V G1691A, and 0.10% (0.06%-0.17%) in relatives with no IT. Given the high absolute risk of VTE in relatives with protein C, protein S, and antithrombin deficiency, we suggest screening for these forms of hereditary thrombophilia in children with VTE and their relatives. Interventional studies are required to assess whether thromboembolism can be prevented in this high-risk population.
Sublytic concentrations of Staphylococcus aureus Panton-Valentine leukocidin alter human PMN gene expression and enhance bactericidal capacity
Authors: Graves Shawna F , Kobayashi Scott D , Braughton Kevin R , Whitney Adeline R , Sturdevant Daniel E , Rasmussen Devon L , Kirpotina Liliya N , Quinn Mark T , DeLeo Frank R
Published: May 2012

PVL-mediated priming of PMNs enhances the host innate immune response.

CA-MRSA infections are often caused by strains encoding PVL, which can cause lysis of PMNs and other myeloid cells in vitro, a function considered widely as the primary means by which PVL might contribute to disease. However, at sublytic concentrations, PVL can function as a PMN agonist. To better understand this phenomenon, we investigated the ability of PVL to alter human PMN function. PMNs exposed to PVL had enhanced capacity to produce O2− in response to fMLF, but unlike priming by LPS, this response did not require TLR signal transduction. On the other hand, there was subcellular redistribution of NADPH oxidase components in PMNs following exposure of these cells to PVL—a finding consistent with priming. Importantly, PMNs primed with PVL had an enhanced ability to bind/ingest and kill Staphylococcus aureus. Priming of PMNs with other agonists, such as IL-8 or GM-CSF, altered the ability of PVL to cause formation of pores in the plasma membranes of these cells. Microarray analysis revealed significant changes in the human PMN transcriptome following exposure to PVL, including up-regulation of molecules that regulate the inflammatory response. Consistent with the microarray data, mediators of the inflammatory response were released from PMNs after stimulation with PVL. We conclude that exposure of human PMNs to sublytic concentrations of PVL elicits a proinflammatory response that is regulated in part at the level of gene expression. We propose that PVL-mediated priming of PMNs enhances the host innate immune response.
Differential Abilities of Chicken Pit1 Isoforms to Regulate the GH Promoter: Evidence for Synergistic Activation
Authors: Mukherjee Malini , Porter Tom E.
Published: May 2012

Pit1, pituitary-specific transcription factor 1, regulates differentiation of cells of the Pit1 lineage in the anterior pituitary and the synthesis of peptide hormones by these cell types, including GH. Pit1 is characterized by an N-terminal transactivation domain and a C-terminal POU domain. Alternative forms of Pit1, differing from each other in the N-terminal domain, have been reported in several species, but the functional implication of having multiple isoforms is not known. Several PIT1 mRNA transcripts exist in chickens that have not been characterized. This study was conducted to determine which, if any, of the chicken Pit1 isoforms regulate the chicken GH (cGH) promoter. During the course of this work, Pit1β2, a novel isoform of chicken Pit1, was discovered. Effects of known and novel isoforms (Pit1α, Pit1β1, Pit1β2, and Pit1γ) on cGH promoter activity were characterized in chicken Leghorn male hepatoma cells. Three of the isoforms, Pit1α, Pit1β1, and Pit1β2, activated the cGH promoter, whereas Pit1γ did not. Results from gel-shift assays indicated that Pit1γ does not bind to the proximal Pit1-bindng site of the cGH promoter, suggesting a possible mechanism underlying its inactivity. We found a functional advantage for having multiple isoforms expressed. When Pit1β1 was coexpressed with Pit1α or Pit1β2, significantly greater activation of the cGH promoter occurred than with any one isoform alone, with synergistic activation occurring when Pit1α and Pit1β1 were coexpressed. Whether this increased activation required, or was facilitated by, heterodimerization of two isoforms is not known. Identification of isoforms with specific functions will facilitate identification of their respective interacting partners that are essential for GH gene expression.
Wtip and Vangl2 are required for mitotic spindle orientation and cloaca morphogenesis
Authors: Bubenshchikova Ekaterina , Ichimura Koichiro , Fukuyo Yayoi , Powell Rebecca , Hsu Chaonan , Morrical Stephen O. , Sedor John R. , Sakai Tatsuo , Obara Tomoko
Published: May 2012

Defects in cilia and basal bodies function are linked to ciliopathies, which result in kidney cyst formation. Recently, cell division defects have been observed in cystic kidneys, but the underlying mechanisms of such defects remain unclear. Wtip is an LIM domain protein of the Ajuba/Zyxin family, but its role in ciliogenesis during embryonic development has not been previously described. We report Wtip is enriched in the basal body and knockdown of wtip leads to pronephric cyst formation, cloaca malformation, hydrocephalus, body curvature, and pericardial edema. We additionally show that wtip knockdown embryos display segment-specific defects in the pronephros: mitotic spindle orientation defects are observed only in the anterior and middle pronephros; cloaca malformation is accompanied by a reduced number of ciliated cells; and ciliated cells lack the striated rootlet that originates from basal bodies, which results in a lack of cilia motility. Our data suggest that loss of Wtip function phenocopies Vangl2 loss of function, a core planar cell polarity (PCP) protein located in the basal body protein. Furthermore, we demonstrate that wtip and vangl2 interact genetically. Taken together, our results indicate that in zebrafish, Wtip is required for mitotic spindle orientation in the anterior and middle of the pronephros, cloaca morphogenesis, and PCP, which may underlie the molecular etiology of ciliopathies.
The bromodomain-containing protein tBRD-1 is specifically expressed in spermatocytes and is essential for male fertility
Authors: Leser Katja , Awe Stephan , Barckmann Bridlin , Renkawitz-Pohl Renate , Rathke Christina
Published: May 2012

By a conserved cellular differentiation process, spermatogenesis leads to formation of haploid sperm for successful reproduction. In Drosophila and in mammals, post-meiotic spermatid differentiation depends on several translationally repressed and stored mRNAs that are often expressed exclusively in the testis through a cell type specific transcriptional program. In Drosophila, the mRNAs of proteins required for post-meiotic chromatin reorganisation, like ProtB and Mst77F, are transcribed in meiotic spermatocytes and subjected to translational repression for days. Transcription of many of these translationally repressed mRNAs depends on testis-specific homologs of TATA box binding protein-associated factors (tTAFs). Here, we identified the testis-specific bromodomain protein, tBRD-1, that is only expressed in primary spermatocytes. Bromodomain proteins are able to recognise and bind acetylated histones and non-histone proteins. We generated tbrd-1 mutant flies and observed that function of tBRD-1 is required for male fertility. tBRD-1 partially colocalised with tTAFs, TAF1 and Polycomb to a Fibrillarin-deficient region within the spermatocyte nucleolus. The nucleolar localisation of tBRD-1 depended on tTAF function but not the other way round. Further, we could show that ectopically expressed tBRD-1-eGFP is able to bind to the interbands of polytene chromosomes. By inhibitor treatment of cultured testis we observed that sub-cellular localisation of tBRD-1 may depend on the acetylation status of primary spermatocytes.
Prolonged exposure to elevated CO2 promotes growth of the algal symbiont Symbiodinium muscatinei in the intertidal sea anemone Anthopleura elegantissima
Authors: Towanda Trisha , Thuesen Erik V.
Published: May 2012

Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO2 on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week at 37 Pa PCO2 and pH 8.1. Clonal pairs were then divided into two groups and maintained for 6 weeks under conditions naturally experienced in their intertidal environment, 45 Pa PCO2, pH 8.1 and 231 Pa PCO2, pH 7.3. Respiration and photosynthesis were measured after the 1-week acclimation period and after 6 weeks in experimental conditions. Density of zooxanthellal cells, zooxanthellal cell size, mitotic index and chlorophyll content were compared between non-clonemate anemones after the 1-week acclimation period and clonal anemones at the end of the experiment. Anemones thrived in hypercapnia. After 6 weeks, A. elegantissima exhibited higher rates of photosynthesis at 45 Pa (4.2 µmol O2 g−1 h−1) and 231 Pa (3.30 µmol O2 g−1 h−1) than at the initial 37 Pa (1.53 µmol O2 g−1 h−1). Likewise, anemones at 231 Pa received more of their respiratory carbon from zooxanthellae (CZAR  = 78.2%) than those at 37 Pa (CZAR  = 66.6%) but less than anemones at 45 Pa (CZAR  = 137.3%). The mitotic index of zooxanthellae was significantly greater in the hypercapnic anemones than in anemones at lower PCO2. Excess zooxanthellae were expelled by their hosts, and cell densities, cell diameters and chlorophyll contents were not significantly different between the groups. The response of A. elegantissima to hypercapnic acidification reveals the potential adaptation of an intertidal, photosynthetic symbiosis for high PCO2.
Force-dependent discharge of nematocysts in the sea anemone Haliplanella luciae (Verrill)
Authors: Todaro Dustin , Watson Glen M.
Published: May 2012

Sea anemones discharge cnidae (‘stinging capsules’ including nematocysts) to capture prey and to defend themselves. In the present study, we tested the relationship between the force of test probes striking feeding tentacles and discharge of microbasic p-mastigophore nematocysts into the test probes. In seawater alone, the response curve is bimodal with maximal discharge observed at 0.33 and 1.10 millinewtons (mN) and with minimal discharge at 1.50 mN. Upon activating chemoreceptors for N-acetylated sugars, maximal discharge is observed across a broad range of smaller forces from 0.16 to 0.9 mN before decreasing to a minimum at 1.50 mN. Likewise, in the presence of nearby vibrations at key frequencies, maximal discharge is observed over a broad range of smaller forces before decreasing to a minimum at 1.50 mN. It appears that sensory input indicating proximity of potential prey expands the range of small forces of impact that stimulate maximal discharge (i.e. to less than 1.10 mN) but not at larger forces of impact (i.e. at approximately 1.50 mN). Thus, contact by small prey would stimulate maximal discharge, and all the more so if such contact is accompanied by specific odorants or by vibrations at specific frequencies. Nevertheless, anemones would not maximally discharge nematocysts into large animals that blunder into contact with their tentacles.
Identification of the ubiquitin ligase Triad1 as a regulator of endosomal transport
Authors: Hassink Gerco , Slotman Johan , Oorschot Viola , Van Der Reijden Bert A. , Monteferrario Davide , Noordermeer Sylvie M. , Van Kerkhof Peter , Klumperman Judith , Strous Ger J.
Published: May 2012

The ubiquitin system plays an important role in trafficking of signaling receptors from the plasma membrane to lysosomes. Triad1 is a ubiquitin ligase that catalyzes the formation of poly-ubiquitin chains linked via lysine-48 as well as lysine-63 residues. We show that depletion of Triad1 affects the sorting of both growth hormone and epidermal growth factor. Triad1-depleted cells accumulate both ligands in endosomes. While fluid phase transport to the lysosomes is reduced in the absence of Triad1, growth hormone receptor can recycle back to the plasma membrane together with transferrin. Using immune electron microscopy we show that Triad1 depletion results in enlarged endosomes with enlarged and irregular shaped intraluminal vesicles. The endosomes display prominent clathrin coats and show increased levels of growth hormone label. We conclude that Triad1 is required for the proper function of multivesicular bodies.
Force field evolution during human blood platelet activation
Authors: Henriques Sarah Schwarz , Sandmann Rabea , Strate Alexander , Köster Sarah
Published: May 2012

Contraction at the cellular level is vital for living organisms. The most prominent type of contractile cells are heart muscle cells, a less well known example are blood platelets. Blood platelets activate and interlink at injured blood vessel sites, finally contracting to form a compact blood clot. They are ideal model cells to study the mechanisms of cellular contraction, as they are simple, bearing no nucleus, and their activation can be triggered and synchronized by the addition of thrombin. Here, we study contraction on the example of human blood platelets employing traction force microscopy, a single cell technique that enables time-resolved measurements of cellular forces on soft substrates with elasticities in the physiological range ∼4 kPa). We find that platelet contraction reaches a steady state after 25 min displaying total forces of ∼34 nN. These forces are considerably larger than what was previously reported for platelets in aggregates, demonstrating the importance of a single cell approach for studies of platelet contraction. Compared to other contractile cells, we find that platelets are particular, because force fields are nearly isotropic with forces pointing toward the center of the cell area.
Enhancement of homocysteine toxicity to insulin-secreting BRIN-BD11 cells in combination with alloxan
Authors: Scullion S M J , Gurgul-Convey E , Elsner M , Lenzen S , Flatt P R , McClenaghan N H
Published: May 2012

Previous studies have shown that homocysteine (HC) has a detrimental impact on insulin secretion and pancreatic beta cell function. The aim of the present study was to determine the role of reactive oxygen species (ROS) in the in vitro toxic effects of HC on insulin secretion and function of BRIN-BD11 insulin-secreting cells. In this study, insulin secretion from BRIN-BD11 cells was determined radioimmunologically, cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and glucokinase activity by a glucose phosphorylation assay following culture with HC plus alloxan (Alx). Treatment with HC resulted in concentration-dependent inhibition of insulin secretion induced by glucose and other insulinotropic agents. HC in combination with Alx resulted in a more pronounced decline in insulin secretion, including that induced by 20 mM alanine, by 43% (P<0.001) and 30 mM KCl by 60% (P<0.001), compared with control culture. The glucokinase phosphorylating capacity in cells cultured with HC plus Alx was significantly lower, compared with control cells. The cells also displayed a significant 84% (P<0.001) decline in cell viability. Prolonged, 72-h culture of insulin-secreting cells with HC followed by 18-h culture without HC did not result in full restoration of beta cell responses to insulinotropic agents. In vitro oxygen consumption was enhanced by a combination of Alx with HC. The study arrived at the conclusion that HC generates ROS in a redox-cycling reaction with Alx that explains the decline in viability of insulin-secreting cells, leading to reduced glucokinase phosphorylating ability, diminished insulin secretory responsiveness and cell death.
Regulation and functional effects of ZNT8 in human pancreatic islets
Authors: Lefebvre Bruno , Vandewalle Brigitte , Balavoine Anne-Sophie , Queniat Gurvan , Moerman Ericka , Vantyghem Marie-Christine , Le Bacquer Olivier , Gmyr Valery , Pawlowski Valérie , Kerr-Conte Julie , Pattou Francois
Published: May 2012

Zinc ions are essential for the formation of insulin crystals in pancreatic β cells, thereby contributing to packaging efficiency of stored insulin. Zinc fluxes are regulated through the SLC30A (zinc transporter, ZNT) family. Here, we investigated the effect of metabolic stress associated with the prediabetic state (zinc depletion, glucotoxicity, and lipotoxicity) on ZNT expression and human pancreatic islet function. Both zinc depletion and lipotoxicity (but not glucotoxicity) downregulatedZNT8(SLC30A8) expression and altered the glucose-stimulated insulin secretion index (GSIS).ZNT8overexpression in human islets protected them from the decrease in GSIS induced by tetrakis-(2-pyridylmethyl) ethylenediamine and palmitate but not from cell death. In addition, zinc supplementation decreased palmitate-induced human islet cell death without restoring GSIS. Altogether, we showed thatZNT8expression responds to variation in zinc and lipid levels in human β cells, with repercussions on insulin secretion. Prospects for increasingZNT8expression and/or activity may prove beneficial in type 2 diabetes in humans.
A caged progesterone analog alters intracellular Ca2+ and flagellar bending in human sperm
Authors: Servin-Vences M Rocio , Tatsu Yoshiro , Ando Hisanori , Guerrero Adán , Yumoto Noboru , Darszon Alberto , Nishigaki Takuya
Published: May 2012

Progesterone is a physiological agonist for mammalian sperm, modulating its flagellar movement and facilitating the acrosome reaction. To study the initial action of progesterone, we developed a caged analog with a photosensitive group: nitrophenylethanediol, at position 20. Using this compound combined with stroboscopic illumination, we performed Ca2+imaging of human spermatozoa and analyzed the effects of progesterone on the intracellular Ca2+concentration ([Ca2+]i) of beating flagella for the first time. We observed a transient [Ca2+]iincrease in the head and the flagellum upon photolysis of the caged progesterone and an increase in flagellar curvature. Detailed kinetic analysis revealed that progesterone elicits an increase in the [Ca2+]iimmediately in the flagellum (mid-piece and principal piece), thereafter in the head with a short time lag. This observation is different from the progesterone-induced Ca2+mobilization in mouse spermatozoa, where the Ca2+rise initiates at the base of the sperm head. Our finding is mostly consistent with the recent discovery that progesterone activates CatSper channels in human spermatozoa, but not in mouse spermatozoa.
Ação de fitoreguladores nos teores de macronutrientes em tomateiro (Lycopersicon esculentum Mill.)
Authors: Castro Paulo R. C.
Published: May 2012

Verificaram-se os efeitos da aplicação de reguladores vegetais na nutrição mineral do tomateiro. Para isto aplicaram-se, em plantas com 4 folhas, cloreto de (2-cloroetil) trimetilamônio (CCC) 2.000 ppm, ácido succínico-2,2-dimetilhidrazida (SADH) 4.000 ppm, ácido giberélico (GA) 100 ppm, ácido (2-cloroetil) fosfônico (CEPA) 200 ppm, ácido 3-indolacético (IAA) 100 ppm e 6-furfurilaminopurina (FAP) na concentração de 500 ppm. Níveis mais elevados de nitrogênio, cálcio e magnésio foram determinados nas hastes de plantas pulverizadas com CCC. Tratamento com CEPA promoveu aumento nos teores de nitrogênio e cálcio nas hastes de tomateiro. Níveis mais elevados de nitrogênio foram determinados nas hastes de plantas tratadas com SADH e FAP. Os reguladores de crescimento utilizados não afetaram os níveis de macronutrientes nas folhas do tomateiro com relação às controle.
Deficiência de macronutrientes, boro e ferro em Eucalyptus urophylla
Authors: Rocha Filho J.V. de C. , Haag H.P. , Oliveira G.D. de
Published: May 2012

Mudas de Eucalyptus urophylla foram cultivadas em soluções nutritivas carentes nos macronutrientes e em boro e ferro, com a finalidade de se obter o quadro sintomatologico das carências de N, P, K, Ca, Mg, S, B e Fe; aquilatar o efeito da omissão e presença dos nutrientes sobre o crescimento e composição química das folhas superiores, medianas e inferiores; assim como do caule e das raízes. Os autores obtiveram em quadro sintomatologico da omissão destes nutrientes, aliados aos seguintes níveis de carência, expresso em função da materia seca: N - 0,69%; P - 0,04%; K - 0,14%; Ca - 0,04%; Mg - 0,05%; S < 0,05%; B - 8,0 ppm; Fe - 50 ppm. A omissão dos elementos da solução nutritiva teve efeito depressivo no crescimento do Eucalyptus, com exceção do tratamento - S que não deferiu do tratamento completo.
Dois processos para a determinação do valor X de Waugh & Fitts (1966), modificado
Authors: Mello Francisco A.F. de
Published: May 2012

São apresentados dois processos para a determinação das quantidades de P a serem adicionadas a amostras de 10 g de terra de modo que, após um período de incubação de 4 dias, 30 ppm de P permaneçam solúveis em 100 ml de solução 0,05 N em HCl e 0,025N em H2SO4. Os processos são os seguintes: a. Baseado na correlação entre as quantidades de P adicionadas as amostras e as extraídas pelo estrator citado; b. Baseado na semelhança dos triângulos obtidos a partir das coordenadas retangulares dos pontos representativos de 30 ppm de P extraído e adicionado e dos pontos imediatamente inferiores e superiores a esse valor. Concluiu-se que os dois processos fornecem resultados equivalentes, sendo indiferente o uso de um ou de outro.
Efeitos da matéria orgânica sobre a capacidade de retenção de umidade de quatro solos do município de Piracicaba
Authors: Mello Francisco de A.F. de , Silveira Ronaldo I. , Arzolla Sylvio , Hellmeister Sylvia R.
Published: May 2012

Foi feito um ensaio de incubação, em vasos, para se verificar o efeito da matéria orgânica (torta de mamona) sobre o poder de retenção de umidade de 4 terras do município de Piracicaba. Conclui-se que tais efeitos foram lineares e significativos a 5% em duas terras e a 1% em outras duas.
Efeitos da nutrição mineral sobre o crescimento, aspecto, composição elementar e fixação de nitrogênio em Azolla
Authors: Malavolta E. , Ruschel A.P. , Medeiros A.A. , Veiga C.L. , Sturion A.C. , Krug F.J. , Escobar L.A. , Igarashi L. , Accorsi W. R. , Barros M.A.A. , Silva A.C. da , Carvalho J.G. , Bellote A.F.J. , Carriel J.M. , Geraldi R.N. , Eimori I.
Published: May 2012

Azolla filiculoides Lam foi cultivado em solução nutritiva arejada, sempre desprovida de N combinado, sendo submetida aos seguintes tratamentos: omissão de P, K, Ca, Mg, S, Fe e Mo, excesso de Mn e Al. As plantas foram colhidas depois de 3 semanas da inoculação. Verificou-se que as deficiências de P, K, Ca e Mg provocaram diminuição na produção de matéria seca e na atividade de nitrogenase. A análise mineral mostrou que: a falta de um elemento provoca redução no seu teor; grande acumulo de Mo; diminuição no teor de Al (do inóculo ou contaminação) no tratamento menos S que garantiu o maior crescimento; efeitos inibitórios ou sinergísticos semelhantes aos descritos no caso de plantas superiores. A toxidez de Al e Mn causou, principalmente a primeira, redução no crescimento e na atividade da nitrogenase. Houve correlações positivas entre: N total e crescimento, atividade de nitrogenase e N total.