16,161 research outputs found
Geriatric oncology: problems with under-treatment within this population
We are currently faced with an aging population, which is rapidly growing worldwide. Two thirds of cancer occurs in the over 65-year age group. Societal conceptions from the past have created ageist stereotypes; old age is associated with frailty and the elderly are perceived to be destined for deterioration and loss of independence. Cancer within the elderly is also subject to these stereotypes, with elderly cancer patients considered by some not as likely to recover as younger patients with cancer. We summarise and review the current concerns regarding elderly management and treatments utilised for the management of oncological disease in the elderly, and discuss the impact of under-treatment within this population
Role of hilar mossy cells in the CA3-dentate gyrus network during sharp wave-ripple activity in vitro
Der Gyrus dentatus (DG) des Hippokampus wird als Eingangsstation für Informationen aus dem entorhinalen Kortex betrachtet. In das DG-Netzwerk sind zwei exzitatorische Zelltypen eingebettet: Körnerzellen, die Signale von dem entorhinalen Kortex empfangen, und Hilus-Mooszellen (MCs), die Signale von Körnerzellen als auch von feedback-Projektionen von CA3-Pyramidenzellen (PCs) empfangen. Postsynaptische Ziele von MC-Projektionen umfassen DG Körnerzellen und verschiedene Interneurone in der selben und in der kontralateralen Hemisphäre des Gehirns. Die Rolle von MCs während rhythmischer Populationsaktivität, und insbesondere während Sharp-Wave / Ripple-Komplexen (SWRs), ist bisher weitgehend unerforscht. SWRs sind prominente Ereignisse im Hippocampus während des Tiefschlafs (Slow wave sleep) und des ruhigen Wachzustandes, und sie sind an der Gedächtniskonsolidierung beteiligt. In der vorliegenden Arbeit, untersuchen wir mithilfe eines in-vitro-Modells von SWRs, inwieweit Mooszellen an SWRs in CA3 beteiligt sind. Mit CA3-Feldpotential-Ableitungen und gleichzeitigen ‚cell-attached‘ Messungen von einzelnen MCs konnten wir beobachten, dass ein wesentlicher Anteil von MCs (47%) während der SWRs in das aktive neuronale Netzwerk rekrutiert werden. Darüber hinaus fanden wir in MCs SWR-assoziierte synaptische Aktivität, bei denen sowohl die exzitatorischen als auch die inhibitorischen Komponenten phasenkohärent und verzögert zur Ripple Oszillation in CA3 auftreten. Simultane Patch-clamp Messungen von CA3-Pyramidenzellen und MCs zeigten längere exzitatorische und inhibitorische Latenzzeiten bei MCs, was die Hypothese einer von CA3 ausgehenden Feedback-Rekrutierung unterstützt. Unsere Daten zeigen zusätzlich, dass das Verhältnis exzitatorischer zu inhibitorischer Aktivität in MCs höher ist als in CA3-Pyramidenzellen, wodurch die MCs mit höherer Wahrscheinlichkeit während SWRs überschwellig aktiviert werden. Schließlich zeigen wir, dass ein signifikanter Anteil (66%) der getesteten Körnerzellen SWR-assoziierte exzitatorische Signale erhalten, im Vergleich zu MCs zeitlich verzögert, was auf eine indirekte Aktivierung von Körnerzellen durch CA3 PCs über MCs hinweist. Zusammengefasst zeigen unsere Daten die aktive Beteiligung von Mooszellen an SWRs und deuten auf eine funktionelle Bedeutung als Schaltstelle für das CA3- Gyrus dentatus Netzwerk in diesem wichtigen physiologischen Netzwerkzustand hin.The dentate gyrus (DG) is considered as the hippocampal input gate for the information arriving from the entorhinal cortex. Embedded into the DG network are two excitatory cell types –granule cells (GCs), which receive inputs from the entorhinal cortex, and hilar mossy cells (MCs), which receive input from GCs and feedback projections from CA3 pyramidal cells (PCs). The postsynaptic targets of MC projections are the GCs and hilar interneurons in both ipsilateral and contralateral hemispheres of the brain. The role of MCs during rhythmic population activity, and in particular during sharp-wave/ripple complexes (SWRs), has remained largely unexplored. SWRs are prominent field events in the hippocampus during slow wave sleep and quiet wakefulness, and are involved in memory consolidation and future planning. In this study, we sought to understand whether MCs participate during CA3 SWRs using an in vitro model of SWRs. With simultaneous CA3 field potential– and cell-attached recordings from MCs, we observed that a significant fraction of MCs (47%) are recruited into the active neuronal network during SWRs. Moreover, MCs receive pronounced, compound, ripple-associated synaptic input where both excitatory and inhibitory components are phase-coherent with and delayed to the CA3 ripple. Simultaneous patch recordings from CA3 pyramidal neurons and MCs revealed longer excitatory and inhibitory latencies in MCs, supporting a feedback recruitment from CA3. Our data also show that the excitatory to inhibitory charge transfer (E/I) ratio in MCs is higher than in the CA3 PCs, making the MCs more likely to spike during SWRs. Finally, we demonstrate that a significant fraction (66%) of tested GCs receive SWR-associated excitatory inputs that are delayed compared to MCs, indicating an indirect activation of GCs by CA3 PCs via MCs. Together, our data suggest the involvement of mossy cells during SWRs and their importance as a relay for CA3-dentate gyrus networks in this important physiological network state
Impact of demographic factors on employee engagement:a study with reference to vasan publications private limited,chennai
Employee plays a vital role in each and every organization; the interest of employee will help to achieve the organization’s objectives. Successful employee engagement strategy creates a community at a work place and not just a work force. When the employees are effectively and positively engaged with their organization, they form an emotional connection with the company. This effects their attitude towards both their colleagues and the company’s client and improves customer satisfaction and services levels.
Employee Engagement Surveys have gained importance among the companies and in this work the researcher has studied the impact of Demographic Variables on Employee Engagement The researcher adopted descriptive research and the data is collected from the employee through convenience sampling method with the help of personally administrated questionnaire containing close ended questions and the sample size is 50. This data was analyzed and classified with the help of statistical tools and the findings and suggestion are extracted from the same
Programmes to Protect the Hungry: Lessons from India
Evidence on calorie intake and nutritional outcomes establishes that chronic hunger and food insecurity persist today on a mass scale in India. The liberalization-induced policy of narrow targeting of the Public Distribution System (PDS), a programme of food security that provides a minimum quantity of cereals at subsidized prices, has resulted in worsening food insecurity. Recent evidence from the 61st round of the National Sample Survey in 2004-2005 establishes that targeting has led to high rates of exclusion of needy households from the system and clear deterioration of coverage in States like Kerala where the universal PDS was most effective.food security, targeting errors, India, liberalization, public distribution
A Laminar Cortical Model for 3D Perception of Slanted and Curved Surfaces and of 2D Images: Developement, attention, and Bistability
A model of laminar visual cortical dynamics proposes how 3D boundary and surface representations of slated and curved 3D objects and 2D images arise. The 3D boundary representations emerge from interactions between non-classical horizontal receptive field interactions with intracorticcal and intercortical feedback circuits. Such non-classical interactions contextually disambiguate classical receptive field responses to ambiguous visual cues using cells that are sensitive to angles and disparity gradients with cortical areas V1 and V2. These cells are all variants of bipole grouping cells. Model simulations show how horizontal connections can develop selectively to angles, how slanted surfaces can activate 3D boundary representations that are sensitive to angles and disparity gradients, how 3D filling-in occurs across slanted surfaces, how a 2D Necker cube image can be represented in 3D, and how bistable Necker cuber percepts occur. The model also explains data about slant aftereffects and 3D neon color spreading. It shows how habituative transmitters that help to control developement also help to trigger bistable 3D percepts and slant aftereffects, and how attention can influence which of these percepts is perceived by propogating along some object boundaries.Air Force Office of Scientific Research (F49620-01-1-0397, F49620-98-1-0108); Defense Advanced Research Projects Agency and the Office of Naval Research (N0014-95-1-0409, N00014-01-1-0624, N00014-95-1-0657); National Science Foundation (IIS-97-20333
The Benefits of Port Liberalization: A Case Study from India
In contrast to the rest of India, where it is the government that predominantly owns and manages ports, the Indian state of Gujarat has implemented various forms of port liberalization since the 1990s. This has helped it become the country's fastest growing state. Gujarat's economy has grown at an average of 10.14 percent per year from fiscal year 2001 to fiscal year 2006, the last five years for which data are available. This is comparable with China's average growth rate since 1978, and is distinctly faster than the growth of the other Asian tigers in the 15 years before the Asian financial crisis of 1997. Gujarat has broken new ground with different forms of privatization, ranging from private provision of port services to completely private ownership of new ports. The process started in the 1980s and gathered momentum rapidly after the central government in New Delhi enacted major economic reforms in the early 1990s. Gujarat has taken advantage of a constitutional loophole to convert its minor ports into some of the biggest ports in the country, vastly improved the availability and efficiency of port infrastructure, and facilitated the development of industrial centers that otherwise would not have existed. Gujarat's port liberalization, along with its status as one of the economically freest states in India, should serve as a model for the rest of India and other developing countries, which can also benefit from the dynamic gains of port privatization
Counterfactual Risk Minimization: Learning from Logged Bandit Feedback
We develop a learning principle and an efficient algorithm for batch learning
from logged bandit feedback. This learning setting is ubiquitous in online
systems (e.g., ad placement, web search, recommendation), where an algorithm
makes a prediction (e.g., ad ranking) for a given input (e.g., query) and
observes bandit feedback (e.g., user clicks on presented ads). We first address
the counterfactual nature of the learning problem through propensity scoring.
Next, we prove generalization error bounds that account for the variance of the
propensity-weighted empirical risk estimator. These constructive bounds give
rise to the Counterfactual Risk Minimization (CRM) principle. We show how CRM
can be used to derive a new learning method -- called Policy Optimizer for
Exponential Models (POEM) -- for learning stochastic linear rules for
structured output prediction. We present a decomposition of the POEM objective
that enables efficient stochastic gradient optimization. POEM is evaluated on
several multi-label classification problems showing substantially improved
robustness and generalization performance compared to the state-of-the-art.Comment: 10 page
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