259 research outputs found
Observations of mixed-species bird flocks at Kichwa Tembo Camp, Kenya
Mixed-species foraging flocks were studied at Kichwa Tembo Camp on the edge of the Masai Mara National Reserve in Kenya between July and September 2004. Observations were made on 29 mixed-species flocks, in which 24 species participated. African Paradise-Flycatcher Terpsiphone viridis, Black-backed Puffback Dryoscopus cubla, Grey-backed Camaroptera Camaroptera brachyura, Collared Sunbird Hedydipna collars and Cabanis's Greenbul Phyllastrephus cabanisi were the most common participants in mixed-species flocks, as well as among the most frequently encountered bird species overall. The Black-backed Puffback was identified as the nuclear species in flocks due to their abundance and frequency with which they were followed by other species. Mixed-species flocks represent another niche dimension in this diverse bird community, but few of these species could be described as flock specialists; most of the birds observed in mixed-species flocks in this study were opportunistic attendant species, including the African Pygmy-Kingfisher Ispidina picta, not previously described as joining mixed-species flocks
Kombinasi Format Factory, U-lead dan Microsoft Office Powerpoint dalam Upaya Meningkatkan Kualitas Media Pembelajaran
Peserta didik mempunyai gaya belajar yang berbeda-beda. Gaya belajar tersebut meliputi auditori, visual dan kinestetik (VAK). Seorang guru harus mampu memenuhi kebutuhan masing-masing gaya belajar peserta didik tersebut. Salah satu cara yang dapat dilakukan adalah dengan menggunakan media pembelajaran berbasis VAK. Media pembelajaran berbasis VAK dapat dipenuhi dengan menyisipkan file video di dalamnya. Selain itu, penggunaan file video sebagai media pembelajaran mendukung implementasi pembelajaran saintifik pada kurikulum 2013. Namun, belum semua guru memiliki kemampuan untuk mengemas file video tersebut dalam bentuk media pembelajaran. Tujuan penelitian ini adalah untuk meningkatkan kemampuan guru-guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran berbasis VAK dengan kombinasi software Format Factory, U-Lead dan PowerPoint. Hasil penelitian menunjukkan bahwa terjadi peningkatan kemampuan para guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran. Peningkatan kemampuan guru-guru tersebut berada di atas target yang direncanakan. Rerata peningkatan kemampuan guru-guru di SMA Negeri 1 Teras 7,87% di atas target, sedangkan di SMA Negeri 1 Boyolali 9,58% di atas target. Kata kunci: Media Pembelajaran, Format Factory, U-Lead, PowerPoint Students have different learning styles. Learning styles include visual learners, auditory learners, and kinesthetic learners. A teacher must be able to fulfill the needs of individual students\u27 learning styles. One way that can be applied is using Visual, Audio and Kinesthetic (VAK) learning media based. VAK-learning media based can be created by inserting video files on it. In addition, using video file as a learning media can support the implementation of scientific learning on the 2013 curriculum. However, not all teachers have the ability to use video files into a learning media. The purpose of this study is to improve the teachers\u27 ability at SMA Negeri 1 Teras and SMAN 1 Boyolali on making VAK-learning media based with a combination of Format Factory, U-Lead and PowerPoint software. The results showed that the teachers\u27 ability on making VAK-learning media based was increased. Increased the teachers\u27 ability was above planned target score. The mean score of the teachers\u27 ability at SMA Negeri 1 Teras 7.87% above the target, while at SMAN 1 Boyolali 9.58% above the target
Exercise and bone health across the lifespan
With ageing, bone tissue undergoes significant compositional, architectural and metabolic alterations potentially leading to osteoporosis. Osteoporosis is the most prevalent bone disorder, which is characterised by progressive bone weakening and an increased risk of fragility fractures. Although this metabolic disease is conventionally associated with ageing and menopause, the predisposing factors are thought to be established during childhood and adolescence. In light of this, exercise interventions implemented during maturation are likely to be highly beneficial as part of a long-term strategy to maximise peak bone mass and hence delay the onset of age- or menopause-related osteoporosis. This notion is supported by data on exercise interventions implemented during childhood and adolescence, which confirmed that weight-bearing activity, particularly if undertaken during peripubertal development, is capable of generating a significant osteogenic response leading to bone anabolism. Recent work on human ageing and epigenetics suggests that undertaking exercise after the fourth decade of life is still important, given the anti-ageing effect and health benefits provided, potentially occurring via a delay in telomere shortening and modification of DNA methylation patterns associated with ageing. Exercise is among the primary modifiable factors capable of influencing bone health by preserving bone mass and strength, preventing the death of bone cells and anti-ageing action provided
Communicating Phylogeny: Evolutionary Tree Diagrams in Museums
Tree of life diagrams are graphic representations of phylogeny—the evolutionary history and
relationships of lineages—and as such these graphics have the potential to convey key evolutionary
ideas and principles to a variety of audiences. Museums play a significant role in teaching about
evolution to the public, and tree graphics form a common element in many exhibits even though
little is known about their impact on visitor understanding. How phylogenies are depicted and used
in informal science settings impacts their accessibility and effectiveness in communicating about
evolution to visitors. In this paper, we summarize the analysis of 185 tree of life graphics collected
from museum exhibits at 52 institutions and highlight some potential implications of how trees are
presented that may support or hinder visitors’ understanding about evolution. While further work is
needed, existing learning research suggests that common elements among the diversity of museum
trees such as the inclusion of anagenesis and absence of time and shared characters might
represent potential barriers to visitor understanding
Monocyte-mediated Tumoricidal Activity via the Tumor Necrosis Factor–related Cytokine, TRAIL
TRAIL (tumor necrosis factor [TNF]-related apoptosis-inducing ligand) is a molecule that displays potent antitumor activity against selected targets. The results presented here demonstrate that human monocytes rapidly express TRAIL, but not Fas ligand or TNF, after activation with interferon (IFN)-γ or -α and acquire the ability to kill tumor cells. Monocyte-mediated tumor cell apoptosis was TRAIL specific, as it could be inhibited with soluble TRAIL receptor. Moreover, IFN stimulation caused a concomitant loss of TRAIL receptor 2 expression, which coincides with monocyte acquisition of resistance to TRAIL-mediated apoptosis. These results define a novel mechanism of monocyte-induced cell cytotoxicity that requires TRAIL, and suggest that TRAIL is a key effector molecule in antitumor activity in vivo
The genome of the versatile nitrogen fixer Azorhizobium caulinodans ORS571
<p>Abstract</p> <p>Background</p> <p>Biological nitrogen fixation is a prokaryotic process that plays an essential role in the global nitrogen cycle. <it>Azorhizobium caulinodans </it>ORS571 has the dual capacity to fix nitrogen both as free-living organism and in a symbiotic interaction with <it>Sesbania rostrata</it>. The host is a fast-growing, submergence-tolerant tropical legume on which <it>A. caulinodans </it>can efficiently induce nodule formation on the root system and on adventitious rootlets located on the stem.</p> <p>Results</p> <p>The 5.37-Mb genome consists of a single circular chromosome with an overall average GC of 67% and numerous islands with varying GC contents. Most nodulation functions as well as a putative type-IV secretion system are found in a distinct symbiosis region. The genome contains a plethora of regulatory and transporter genes and many functions possibly involved in contacting a host. It potentially encodes 4717 proteins of which 96.3% have homologs and 3.7% are unique for <it>A. caulinodans</it>. Phylogenetic analyses show that the diazotroph <it>Xanthobacter autotrophicus </it>is the closest relative among the sequenced genomes, but the synteny between both genomes is very poor.</p> <p>Conclusion</p> <p>The genome analysis reveals that <it>A. caulinodans </it>is a diazotroph that acquired the capacity to nodulate most probably through horizontal gene transfer of a complex symbiosis island. The genome contains numerous genes that reflect a strong adaptive and metabolic potential. These combined features and the availability of the annotated genome make <it>A. caulinodans </it>an attractive organism to explore symbiotic biological nitrogen fixation beyond leguminous plants.</p
The diagnostic value of liver biopsy
BACKGROUND: Since the introduction of molecular diagnostic tools such as markers for hepatitis C and different autoimmune diseases, liver biopsy is thought to be useful mainly for staging but not for diagnostic purposes. The aim was to review the liver biopsies for 5 years after introduction of testing for hepatitis C, in order to evaluate what diagnostic insights – if any – remain after serologic testing. METHODS: Retrospective review of all liver biopsies performed between 1.1.1995 and 31.12.1999 at an academic outpatient hepatology department. The diagnoses suspected in the biopsy note were compared with the final diagnosis arrived at during a joint meeting with the responsible clinicians and a hepatopathologist. RESULTS: In 365 patients, 411 diagnoses were carried out before biopsy. 84.4 % were confirmed by biopsy but in 8.8 %, 6.8 % and 10.5 % the diagnosis was specified, changed or a diagnosis added, respectively. Additional diagnoses of clinical relevance were unrecognized biliary obstruction and additional alcoholic liver disease in patients with chronic hepatitis C. Liver biopsy led to change in management for 12.1 % of patients. CONCLUSION: Even in the era of advanced virological, immunological and molecular genetic testing, liver biopsy remains a useful diagnostic tool. The yield is particularly high in marker negative patients but also in patients with a clear-cut prebiopsy diagnosis, liver biopsy can lead to changes in patient management
Targeted Drug Delivery by Gemtuzumab Ozogamicin: Mechanism-Based Mathematical Model for Treatment Strategy Improvement and Therapy Individualization
Gemtuzumab ozogamicin (GO) is a chemotherapy-conjugated anti-CD33 monoclonal antibody effective in some patients with acute myeloid leukemia (AML). The optimal treatment schedule and optimal timing of GO administration relative to other agents remains unknown. Conventional pharmacokinetic analysis has been of limited insight for the schedule optimization. We developed a mechanism-based mathematical model and employed it to analyze the time-course of free and GO-bound CD33 molecules on the lekemic blasts in individual AML patients treated with GO. We calculated expected intravascular drug exposure (I-AUC) as a surrogate marker for the response to the drug. A high CD33 production rate and low drug efflux were the most important determinants of high I-AUC, characterizing patients with favorable pharmacokinetic profile and, hence, improved response. I-AUC was insensitive to other studied parameters within biologically relevant ranges, including internalization rate and dissociation constant. Our computations suggested that even moderate blast burden reduction prior to drug administration enables lowering of GO doses without significantly compromising intracellular drug exposure. These findings indicate that GO may optimally be used after cyto-reductive chemotherapy, rather than before, or concomitantly with it, and that GO efficacy can be maintained by dose reduction to 6 mg/m2 and a dosing interval of 7 days. Model predictions are validated by comparison with the results of EORTC-GIMEMA AML19 clinical trial, where two different GO schedules were administered. We suggest that incorporation of our results in clinical practice can serve identification of the subpopulation of elderly patients who can benefit most of the GO treatment and enable return of the currently suspended drug to clinic
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