The Changing Face of the Elementary School Principal

Principals in today’s schools have more experience, have more education, and are of a more advanced age than ever before (National Association of Elementary School Principals [NAESP], 2006). Women elementary principals in the nation have increased from 41% to 56%. Likewise, the age of principals at all levels has increased, as did the percentage of principals who had more than 20 years of experience before entering the position (NAESP, 2006). In addition, the number of elementary principals has increased by 7,000 over the past 10 years (NAESP, 2004, 2005); this number grew to 61,000 in 2003-2004 from 54,000 in 1993-1994. Of these 61,000 principals, approximately 14,000 served schools in rural areas, 17,000 served schools in urban areas, and 31,000 served schools in suburban areas. Thus, more than half of the elementary principals in this country currently serve schools that are classified as suburban. In addition, the number of principals of all levels increased during the same 10-year span from 104,600 to 115,000 and more than half of all principals in the United States work at elementary schools (NAESP, 2005). Therefore, an understanding of the largest group of principals and their characteristics is important for many reasons

Phase II Trial of Dolastatin-10, a Novel Anti-Tubulin Agent, in Metastatic Soft Tissue Sarcomas

Patients:Soft tissue sarcomas are uncommon malignancies with few therapeutic options for recurrent or metastatic disease. Dolastatin-10 (Dol-10) is a pentapeptide anti-microtubule agent that binds to tubulin sites distinct from vinca alkaloids. Based on the novel mechanism of action, limited activity of other anti-microtubular agents, and anti-neoplastic activity in pre-clinical screening of Dol-10, this multi-institutional phase II study was conducted to determine the objective response rate of Dol-10 in recurrent or metastatic soft tissue sarcomas that had not been treated with chemotherapy outside of the adjuvant setting

Communities, Knowledge Creation, and Information Diffusion

In this paper, we examine how patterns of scientific collaboration contribute to knowledge creation. Recent studies have shown that scientists can benefit from their position within collaborative networks by being able to receive more information of better quality in a timely fashion, and by presiding over communication between collaborators. Here we focus on the tendency of scientists to cluster into tightly-knit communities, and discuss the implications of this tendency for scientific performance. We begin by reviewing a new method for finding communities, and we then assess its benefits in terms of computation time and accuracy. While communities often serve as a taxonomic scheme to map knowledge domains, they also affect how successfully scientists engage in the creation of new knowledge. By drawing on the longstanding debate on the relative benefits of social cohesion and brokerage, we discuss the conditions that facilitate collaborations among scientists within or across communities. We show that successful scientific production occurs within communities when scientists have cohesive collaborations with others from the same knowledge domain, and across communities when scientists intermediate among otherwise disconnected collaborators from different knowledge domains. We also discuss the implications of communities for information diffusion, and show how traditional epidemiological approaches need to be refined to take knowledge heterogeneity into account and preserve the system's ability to promote creative processes of novel recombinations of idea

Bartonella quintana coinfection with Mycobacterium avium complex and CMV in an AIDS patient: case presentation

BACKGROUND: As a greater number of HIV-infected patients survive despite profound immunodepression due to medical progress, we face complex infection with multiple agents in AIDS-patients. CASE PRESENTATION: We report the case of an AIDS patient with a primary clinical presentation suggestive of bacillary angiomatosis. We also found in cutaneous lesions Mycobacterium avium complex and cytomegalovirus. CONCLUSION: This clinical case illustrates the possibility of multiple coinfections in AIDS patients and the need to be exhaustive in evaluating infectious diseases in severely immunocompromised patients

Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin

Relative expression of mRNAs related to cavitation process in bovine embryos produced in vivo and in vitro

The objectives of this work were to identify and to evaluate possible differences on gene expression of aquaporins and Na/K-ATPases transcripts between embryos in vivo and in vitro produced. For each group, 15 blastocysts distributed in three pools were used for RNA extraction followed by amplification and reverse transcription. The resulting cDNAs were submitted to Real-Time PCR, using the GAPDH gene as endogenous control. It was not possible to identify AQP1 transcripts. Relative expression of AQP3 (1.33 ± 0.78) and AQP11 (2.00 ± 1.42) were not different in blastocysts in vitro and in vivo produced. Na/K-ATPase α1 gene (2.25 ± 1.07) was overregulated whereas Na/K-ATPase β2 transcripts 0.40 ± 0.30) did not differ among blastocysts produced in vitro from those produced in vivo. Transcripts for gene AQP1 are not present in bovine blastocysts. In vitro culture system does not alter expression of genes AQP3, AQP11 and Na/K-ATPase β2 genes, however, it affects expression of Na/K-ATPase α1.Os objetivos neste trabalho foram identificar e avaliar possíveis diferenças na expressão gênica de transcritos de Aquaporina e ATPases-Na/K presentes em embriões produzidos in vivo e in vitro. Para cada grupo, 15 blastocistos distribuídos em três conjuntos foram utilizados para a extração do RNA, seguida da amplificação e da transcrição reversa. Os DNAs complementares foram submetidos à reação em cadeia da enzima polimerase em tempo real, utilizando-se o gene GAPDH como controle endógeno. Não foi possível identificar transcritos de AQP1. A expressão relativa dos genes AQP3 (1,33 ± 0,78) e AQP11 (2,00 ± 1,42) não foi diferente em blastocistos produzidos in vitro e in vivo. O gene ATPase-Na/K α1 (2,25 ± 1,07) encontrou-se sobrerregulado, enquanto o gene ATPase-Na/K β2 (0,40 ± 0,30) não diferiu entre os blastocistos produzidos in vitro e aqueles produzidos in vivo. Transcritos para o gene AQP1 não estão presentes em blastocistos bovinos. O sistema de cultivo in vitro não influencia a expressão dos genes AQP3, AQP11 e ATPase-Na/K β2, porém altera a expressão do gene ATPase-Na/K α1

Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group.

The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients

Customisation of the Exome Data Analysis Pipeline Using a Combinatorial Approach

The advent of next generation sequencing (NGS) technologies have revolutionised the way biologists produce, analyse and interpret data. Although NGS platforms provide a cost-effective way to discover genome-wide variants from a single experiment, variants discovered by NGS need follow up validation due to the high error rates associated with various sequencing chemistries. Recently, whole exome sequencing has been proposed as an affordable option compared to whole genome runs but it still requires follow up validation of all the novel exomic variants. Customarily, a consensus approach is used to overcome the systematic errors inherent to the sequencing technology, alignment and post alignment variant detection algorithms. However, the aforementioned approach warrants the use of multiple sequencing chemistry, multiple alignment tools, multiple variant callers which may not be viable in terms of time and money for individual investigators with limited informatics know-how. Biologists often lack the requisite training to deal with the huge amount of data produced by NGS runs and face difficulty in choosing from the list of freely available analytical tools for NGS data analysis. Hence, there is a need to customise the NGS data analysis pipeline to preferentially retain true variants by minimising the incidence of false positives and make the choice of right analytical tools easier. To this end, we have sampled different freely available tools used at the alignment and post alignment stage suggesting the use of the most suitable combination determined by a simple framework of pre-existing metrics to create significant datasets