6,300 research outputs found
Differences in performance and kinematics when catching under block versus random temporal constraints
Postural adjustments in catching: on the interplay between segment stabilization and equilibrium control
The purpose of this study was to investigate postural adjustments in one-handed ball catching. Specifically, the functional role of anticipatory postural adjustments (APA) during the initial arm raising and subsequent postural adjustments (SPA) for equilibrium control and ball-hand impact were scrutinized. Full-body kinematics and kinetics allowed an analysis of the mechanical consequences of raising up the arm and preparing for ball-hand impact. APA for catching were suggested to be for segment stabilization. SPA had a functional role for equilibrium control by an inverted pendulum mechanism but were also involved in preparing for the impact of the ball on the hand, which was illustrated by an increased postural response at the end of the movement. These results were compared with raising up the arm in a well-studied reaction-time task, for which an additional counter rotation equilibrium mechanism was observed. Together, our findings demonstrate that postural adjustments should be investigated in relation to their specific functional task constraints, rather than generalizing the functional role of these postural adjustments over different tasks
A biological pathway linking inflammation and depression: activation of indoleamine 2,3-dioxygenase
This article highlights the evidence linking depression to increased inflammatory drive and explores putative mechanisms for the association by reviewing both preclinical and clinical literature. The enzyme indoleamine 2,3-dioxygenase is induced by proinflammatory cytokines and may form a link between immune functioning and altered neurotransmission, which results in depression. Increased indoleamine 2,3-dioxygenase activity may cause both tryptophan depletion and increased neurotoxic metabolites of the kynurenine pathway, two alterations which have been hypothesized to cause depression. The tryptophan-kynurenine pathway is comprehensively described with a focus on the evidence linking metabolite alterations to depression. The use of immune-activated groups at high risk of depression have been used to explore these hypotheses; we focus on the studies involving chronic hepatitis C patients receiving interferon-alpha, an immune activating cytokine. Findings from this work have led to novel strategies for the future development of antidepressants including inhibition of indoleamine 2,3-dioxygenase, moderating the cytokines which activate it, or addressing other targets in the kynurenine pathway
Making it real: exploring the potential of Augmented Reality for teaching primary school science
The use of Augmented Reality (AR) in formal education could prove a key component in future learning environments that are richly populated with a blend of hardware and software applications. However, relatively little is known about the potential of this technology to support teaching and learning with groups of young children in the classroom. Analysis of teacher-child dialogue in a comparative study between use of an AR virtual mirror interface and more traditional science teaching methods for 10-year-old children, revealed that the children using AR were less engaged than those using traditional resources. We suggest four design requirements that need to be considered if AR is to be successfully adopted into classroom practice. These requirements are: flexible content that teachers can adapt to the needs of their children, guided exploration so learning opportunities can be maximised, in a limited time, and attention to the needs of institutional and curricular requirements
Plant communities affect arbuscular mycorrhizal fungal diversity and community composition in grassland microcosms
The diversity of arbuscular mycorrhizal (AM) fungi was investigated in an unfertilized limestone grassland soil supporting different synthesized vascular plant assemblages that had developed for 3 yr. The experimental treatments comprised: bare soil; monocultures of the nonmycotrophic sedge Carex flacca; monocultures of the mycotrophic grass Festuca ovina; and a species-rich mixture of four forbs, four grasses and four sedges. The diversity of AM fungi was analysed in roots of Plantago lanceolata bioassay seedlings using terminal-restriction fragment length polymorphism (T-RFLP). The extent of AM colonization, shoot biomass and nitrogen and phosphorus concentrations were also measured. The AM diversity was affected significantly by the floristic composition of the microcosms and shoot phosphorus concentration was positively correlated with AM diversity. The diversity of AM fungi in P. lanceolata decreased in the order: bare soil > C. flacca > 12 species > F. ovina. The unexpectedly high diversity in the bare soil and sedge monoculture likely reflects differences in the modes of colonization and sources of inoculum in these treatments compared with the assemblages containing established AM-compatible plants
Quantifying trading behavior in financial markets using Google Trends
Crises in financial markets affect humans worldwide. Detailed market data on trading decisions reflect some of the complex human behavior that has led to these crises. We suggest that massive new data sources resulting from human interaction with the Internet may offer a new perspective on the behavior of market participants in periods of large market movements. By analyzing changes in Google query volumes for search terms related to finance, we find patterns that may be interpreted as “early warning signs” of stock market moves. Our results illustrate the potential that combining extensive behavioral data sets offers for a better understanding of collective human behavior
BRCA1 and BRCA2 mutations in a population-based study of male breast cancer
Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC)
in the United Kingdom is not known, and the importance of these genes in the increased risk of female
breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear.
Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We
screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these
cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the
contribution of BRCA1 and BRCA2 to this risk.
Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also
had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4
times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation
carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a
mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8%
(95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or
pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast
cancer in female first-degree relatives.
Conclusion: These data suggest that other genes that confer an increased risk for both female and
male breast cancer have yet to be found
Linking dwarf galaxies to halo building blocks with the most metal-poor star in Sculptor
Current cosmological models indicate that the Milky Way's stellar halo was
assembled from many smaller systems. Based on the apparent absence of the most
metal-poor stars in present-day dwarf galaxies, recent studies claimed that the
true Galactic building blocks must have been vastly different from the
surviving dwarfs. The discovery of an extremely iron-poor star (S1020549) in
the Sculptor dwarf galaxy based on a medium-resolution spectrum cast some doubt
on this conclusion. However, verification of the iron-deficiency and
measurements of additional elements, such as the alpha-element Mg, are
mandatory for demonstrating that the same type of stars produced the metals
found in dwarf galaxies and the Galactic halo. Only then can dwarf galaxy stars
be conclusively linked to early stellar halo assembly. Here we report
high-resolution spectroscopic abundances for 11 elements in S1020549,
confirming the iron abundance of less than 1/4000th that of the Sun, and
showing that the overall abundance pattern mirrors that seen in low-metallicity
halo stars, including the alpha-elements. Such chemical similarity indicates
that the systems destroyed to form the halo billions of years ago were not
fundamentally different from the progenitors of present-day dwarfs, and
suggests that the early chemical enrichment of all galaxies may be nearly
identical.Comment: 16 pages, including 2 figures. Accepted for publication in Nature. It
is embargoed for discussion in the press until formal publication in Natur
Nummular keratopathy in a patient with Hyper-IgD Syndrome
<p>Abstract</p> <p>Purpose</p> <p>To report a case of recurrent nummular keratitis in a pediatric patient with Hyperimmunoglobulinemia D syndrome.</p> <p>Methods</p> <p>A retrospective chart review.</p> <p>Results</p> <p>A 14-year-old boy with Hyperimmunoglobulinemia D syndrome (HIDS) presented with photophobia and ocular irritation concomitant with disease exacerbation. He was found on exam to have significant nummular keratitis, which responded to a short course of topical steroids. Despite acute response to local immunosuppression, the patient had several recurrent attacks and eventually developed a large corneal scar and decreased vision. After initiation of infliximab therapy his ocular sequelae improved dramatically and his vision returned to 20/20.</p> <p>Conclusion</p> <p>One possible form of end-organ damage associated with HIDS is vision threatening nummular keratopathy.</p
Testicular seminoma – unusual histology and staging with sub epithelial spread of seminoma along the vas deferans
BACKGROUND: The route of local and metastatic spread of testicular seminoma is well recognised and accepted. The spread is via lymphatics to the paraaortic nodes. CASE PRESENTATION: We present a case report of testicular seminoma in a 56 year old man with previously unreported histological findings. In this case seminoma tumour cells did not appear to have spread by the expected lymphatic route. There was no involvement of retro-peritoneal para-aortic lymph nodes. The tumour appeared to have spread directly along the vas deferans in the sub epithelial plane to the mesenteric lymph nodes. CONCLUSION: This type of seminoma tumour spread has not previously been described and it is not a recognised route for metastasis by seminoma tumour. In this case the macroscopic clinical appearance was of a stage I tumour with normal tumour markers. However, the pathological stage of the tumour was surprisingly increased to stage III on the basis of histology and CT radiological findings. We present the unusual histological findings. In view of this unusual histological finding we reinforce the need for accurate staging and for resection of the spermatic cord close to the deep inguinal ring. Accurate staging is crucial in planning the treatment and follow up of seminoma and determines the prognosis
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