bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometric and energetic criteria for the free boundary regularity in an obstacle-type problem
Authors: Petrosyan Arshak , Shahgholian Henrik
Published: December 2007

We consider an obstacle-type problem Δu = f(x)χΩ�����in D, u = |∇u| = 0�����on D \ Ω, where D is a given open set in ℝn and Ω is an unknown open subset of D. The problem originates in potential theory, in connection with harmonic continuation of potentials. The qualitative difference between this problem and the classical obstacle problem is that the solutions here are allowed to change sign. Using geometric and energetic criteria in delicate combination we show the C1,1 regularity of the solutions, and the regularity of the free boundary, below the Lipschitz threshold for the right-hand side.
Countable state shifts and uniqueness of g -measures
Authors: Johansson Anders , Öberg Anders , Pollicott Mark
Published: December 2007

In this paper we present a new approach to studying g-measures which is based upon local absolute continuity. We extend an earlier result that square summability of variations of g ensures uniqueness of g-measures. The first extension is to the case of countably many symbols. The second extension is to some cases where g ≥ 0, relaxing the earlier requirement that inf g > 0.
Schur positivity and Schur log-concavity
Authors: Lam Thomas , Postnikov Alexander , Pylyavskyy Pavlo
Published: December 2007

We prove Okounkov's conjecture, a conjecture of Fomin-Fulton-Li-Poon, and a special case of Lascoux-Leclerc-Thibon's conjecture on Schur positivity and give several more general statements using a recent result of Rhoades and Skandera. We also give an intriguing log-concavity property of Schur functions.
Algebraic cycles and Mumford-Griffiths invariants
Authors: Lewis James D , Saito Shuji
Published: December 2007

Let X be a projective algebraic manifold and let CHr (X) be the Chow group of algebraic cycles of codimension r on X, modulo rational equivalence. Working with a candidate Bloch- Beilinson filtration {Fν}ν≥0 on CHr (X) ⊗ ℚ due to the second author, we construct a space of arithmetic Hodge theoretic invariants ∇Jr,ν(X) and corresponding map ϕr,ν X : GrνF CHr (X)⊗ℚ → ∇Jr,ν(X), and determine conditions on X for which the kernel and image of ϕr,νX are "uncountably large".
Scientific Method for Medical Practitioners: The Case Method of Teaching Pathology in Early Twentieth-Century Edinburgh
Authors: Sturdy Steve
Published: December 2007

The appointment of James Lorrain Smith as first full-time professor of pathology at the University of Edinburgh in 1912 led to a series of reforms in pathology teaching there. Most significant was the inception of what Lorrain Smith called the "case method of teaching pathology," which used the investigation of clinical cases as the basis for a series of exercises in clinico-pathological correlation. This paper examines the social and cognitive organization of the case method of teaching, and shows how such exercises were expected to inform the students' future medical training and practice. In so doing, it also throws light on the relationship between medical science and clinical practice that obtained in Edinburgh at that time. [End Page 760]
Lying-in and Laying-out: Fetal Health and the Contribution of Midwifery
Authors: Woods Robert
Published: December 2007

This article considers the quality of midwifery skills and practice principally in eighteenth-, nineteenth-, and early twentieth-century England. It discusses the merits of assessing effectiveness via differentials and changes in late-fetal rather than maternal mortality. Evidence from the lying-in hospitals, both in-patients and out-patients, in terms of stillbirths and the deaths of mothers and children is set against what is known from demographic studies of the background levels of early-age and maternal mortality. The conclusions emphasize the value of taking a "fetal health" perspective, rather than viewing midwifery simply in terms of maternal well-being. They also note the apparent superiority of London's position compared with the provinces and the steady improvement during the eighteenth century, and lack of progress during the nineteenth; and they reconfirm the particular dangers to mothers delivered as hospital in-patients. Finally, the considerable methodological problems faced by such studies are emphasized.
Clinician and Revolutionary: Frantz Fanon, Biography, and the History of Colonial Medicine
Authors: Keller Richard C. (Richard Charles)
Published: December 2007

Although scholars have exhibited close interest in the life and work of Frantz Fanon, few have emphasized his work as a psychiatrist. This essay surveys recent books and films that have placed Fanon's clinical experience at the center of his life's work. It concludes that historians of colonial medicine have much to gain from these works and their reexaminations of a controversial figure.
Biotypology, Endocrinology, and Sterilization: The Practice of Eugenics in the Treatment of Argentinian Women during the 1930s
Authors: Eraso Yolanda
Published: December 2007

This article looks at medical approaches to women's fertility in Argentina in the 1930s and explores the ways in which eugenics encouraged the reproduction of the fit and attempted to avoid the reproduction of the unfit. The analysis concentrates on three main aspects: biotypology (the scientific classification of bodies), endocrine therapy, and sterilization. The article concludes by suggesting that a eugenically oriented obstetrical and gynecological practice encouraged both endocrine treatments (to achieve the ideal fertile woman) and sterilization, which, in spite of being legally banned, found a subtle application.
Direct Reference, Empty Names and Implicature
Authors: Green Mitchell S.
Published: December 2007

Angle Grinder Man removes wheel locks from cars in London. He is something of a folk hero, saving drivers from enormous parking and towing fines, and has succeeded thus far in eluding the authorities. In spite of his cape and lamé tights, he is no fiction; he's a real person. By contrast, Pegasus, Zeus and the like are fictions. None of them is real. In fact, not only is each of them different from the others, all differ from Angle Grinder Man. After all, Zeus throws thunderbolts but doesn't remove boots from cars; unlike Superman, Angle Grinder Man couldn't leap over a parked Mini, and all sightings suggest that he is a human being, not a horse.
Spinoza's Normative Ethics
Authors: LeBuffe Michael
Published: December 2007

Spinoza presents his ethics using a variety of terminologies. Propositions that are, or at least might be taken for, normative include only very few explicit guidelines for action. I will take this claim from Vp10s to be one such guideline:

Vp10s: So that we may always have this rule of reason ready when it is needed, we should think and meditate often about common human wrongs and how and in what way they may best be driven away by nobility.
Field Metaphysic, Power, and Individuation in Spinoza
Authors: Viljanen Valtteri
Published: December 2007

Spinoza developed a highly interesting metaphysical theory of nature and individuality. In this paper, I endeavor to bring forward some ideas on how Spinozistic views on extended substance, physical world, and individuality can be approached using the concept of power as the basis of interpretation. Jonathan Bennett's ‘field metaphysical’ interpretation of Spinoza's doctrine of one extended substance has generated much discussion, and forms the other starting point of my paper. I believe that the field metaphysical interpretation enables one to deal with the central questions concerning physical individuation — individuality and the persistence of individual being — in a rather novel way. My main question is this: what follows if physical individuals are seen as parts of a unified field of extended power?
Empty Names and Pragmatic Implicatures
Authors: Adams Fred , Fuller Gary
Published: December 2007

What are the meanings of empty names such as ‘Vulcan,’ ‘Pegasus,’ and ‘Santa Claus’ in such sentences as ‘Vulcan is the tenth planet,’ ‘Pegasus flies,’ and especially ‘Santa Claus does not exist’?

Our view, developed in Adams et al. (1992, 1994, 1997, 2004), consists of a direct-reference account of the meaning of empty names in combination with a pragmatic-implicature account of why we have certain intuitions that seem to conflict with a direct-reference account.
Teleology Without Tears: Aristotle and the Role of Mechanistic Conceptions of Organisms
Authors: Berryman Sylvia
Published: December 2007

In this paper I outline a role for mechanistic conceptions of organisms in ancient Greek natural philosophy, especially the study of organisms. By ‘mechanistic conceptions’ I mean the use of ideas and techniques drawn from the field of mechanics to investigate the natural world. ‘Mechanistic conceptions’ of organisms in ancient Greek philosophy, then, are those that draw on the ancient understanding of the field called ‘mechanics’ — hê mêchanikê technê—to investigate living things, rather than those bearing some perceived similarity to modern notions of ‘the mechanical.’ I have argued elsewhere that evidence of mechanistic conceptions of the natural world can be found, not only among seventeenth and eighteenth century ‘mechanical philosophers,’ but also—albeit in vestigial form — in some ancient Greek texts. Unfortunately, these reports are slight, often by detractors of this approach, and offer only clues as to the motivational context for employing these mechanical conceptions. Here, my purpose is to suggest what role they might have played in the history of natural philosophy.
Conflicts of Rules in Hooker's Rule-Consequentialism
Authors: Eggleston Ben
Published: December 2007

It is the business of ethics to tell us what are our duties.

—John Stuart Mill

Just about any proponent of a rule-based theory of morality must eventually confront the question of how to resolve conflicts among the rules that the theory endorses. Is there a priority rule specifying which rules must yield to which, as in Rawls's lexical ordering of the first principle of his theory of justice over the second? Must the agent intuitively balance considerations, as in certain forms of intuitionist pluralism? Or might there be some other conflict-resolving provision? Brad Hooker, a defender of a rule-based theory of morality that he calls ‘rule-consequentialism,’ confronts this question about conflicts of rules in his recent bookIdeal Code, Real World: A rule-Consequentialism Theory of Morality. In this paper, I examine Hooker's answer to this question, and I argue that his answer fails to solve a serious problem that arises from such conflicts.
Perceptions of Methadone Maintained Clients About Barriers and Facilitators to Help-Seeking Behavior
Authors: Nyamathi Adeline , Smith Donna McNeese , Shoptaw Steven , Mutere Malaika , Cohen Allan , Amrani Israel , Morales Louis , Castro Viviane de
Published: December 2007

Background: Among substance users, health seeking remains a major challenge for which few data are available. Objectives: We sought to investigate the perceptions of methadone-maintained heroin users who are also problem or heavy drinkers, their barriers and facilitators to seeking help for substance and general and chronic care treatment. Methods: A qualitative design using a semistructured focus group approach was conducted with a convenience sample of 41 adult clients of a methadone maintenance facility in Los Angeles. Results: Findings revealed that discrimination was a major challenge experienced as a result of their methadone status. Lack of primary care providers, limited access to health care facilities and access barriers were pervasive. Focus group participants expressed a desire for nonjudgemental and empathetic care that would foster respect and facilitate help-seeking behaviors through a comprehensive support system. Conclusions: The need to design culturally relevant training programs was evident which included an integration of treatment, communication and societal issues.
Systematic Review of U.S.-Based Randomized Controlled Trials Using Community Health Workers
Authors: Gibbons M. Christopher , Tyus Nadra C
Published: December 2007

Background: There is increasing concern about racial and ethnic disparities in health status and health care in the United States (U.S.). Recent recommendations to address these disparities have encouraged the use of community health workers (CHWs) as a promising intervention. Objectives: The purpose of this review is to provide a systematic examination of randomized controlled trial (RCT) evidence regarding the usefulness of CHWs in the U.S. health care system. Methods: We searched electronic databases from January 1, 1990, to June 7, 2007, to identify RCTs using CHWs. Two researchers systematically reviewed all eligible articles. Data were extracted from each eligible study and independently reviewed by both investigators. Results: Twelve studies were eligible for inclusion in this review. Of those 12 studies, 10 demonstrated CHW efficacy in enhancing outcomes. Three of these studies addressed breast cancer screening behaviors and three evaluated Pap smear testing. The review found one study each in the areas of patient enrollment in research, early intervention services, child development, blood pressure reduction and control, and nutritional eating habits. Conclusions: Although significant heterogeneity among studies precluded pooling of data and meta-analyses, the weight of the available RCT evidence suggests positive benefits may be attributable to the use of CHWs interventional strategy in the context of the U.S. health care setting.
Use of EPA Collaborative Problem-Solving Model to Obtain Environmental Justice in North Carolina
Authors: Wilson Sacoby M. (Sacoby Miguel) , Wilson Omega R , Heaney Christopher D , Cooper John
Published: December 2007

Background: The West End Revitalization Association (WERA), a community-based organization (CBO) in Mebane, North Carolina, was awarded a Collaborative Problem-Solving (CPS) grant from the U.S. Environmental Protection Agency's Office of Environmental Justice (EPA OEJ). Objectives: The purpose of this paper is to highlight WERA's efforts to bring stakeholders in three low-income African-American communities where environmental hazards created public health risks together for collaboration rather than litigation. Methods: WERA's board and staff organized nine working groups with specific areas of expertise that would facilitate research, identify lack of basic amenities, and encourage funding for corrective action and participation in progress reporting workshops. WERA used consensus building, dispute resolution, and resource mobilization as part of the CPS model to address noncompliance with environmental laws, including the Clean Air Act, Clean Water Act, Safe Drinking Water Act, Toxic Substances Control Act, and Solid Waste Disposal Act. Results: WERA's CPS "Right to Basic Amenities" project produced a framework for (1) grassroots management and ownership of a collaborative problem-solving process; (2) bringing stakeholders together with diverse and conflicting viewpoints; (3) implementation of an innovative community-owned and managed (COMR) research model; and (4) leveraging millions of dollars to fund installation of first-time municipal water/sewer services, street paving, and relocation of the 119-bypass to advance environmental health solutions. Conclusion: The structure and successes of WERA's Right to Basic Amenities project have been discussed at demonstration and training sessions to help others replicate the model in comparable low-income communities of color in North Carolina and across the United States.
The West End Revitalization Association's Community-Owned and -Managed Research Model: Development, Implementation, and Action
Authors: Heaney Christopher D , Wilson Sacoby M. (Sacoby Miguel) , Wilson Omega R
Published: December 2007

Background: Principal investigators (PIs) of community-based projects are predominantly university faculty who partner with community-based organizations (CBOs) to find a place to conduct research in communities that will cooperate with their research objectives. University-managed research models (UMRMs) are not always beneficial for CBOs because the university usually manages the study, collects and owns the data, and leverages control at each stage of research, without priority to resolution of problems impacting the quality of life of participating communities. Objectives: We present the principles of community-owned and -managed research (COMR), as a new community-driven research model developed by the West End Revitalization Association (WERA), a CBO in Mebane, North Carolina. Methods: We describe WERA's development of COMR, compare the power hierarchies of COMR with traditional UMRMs, distinguish COMR partnerships from UMRM partnerships, discuss disbursement of funds, and control/ownership of data. As the PI of research activities, WERA drafted Memoranda of Agreement (MOAs) for all partners, including academic researchers, implemented quality assurance and control procedures, submitted community research protocols for institutional review, and retained data ownership for action, activism, and problem solving. COMR methods encouraged corrective action of environmental justice (EJ) problems in affected communities, including provision of public, regulated drinking water and sewer services. Conclusions: COMR promotes CBOs with demonstrated organizational capacity to PI and project manager. The COMR model goes beyond UMRMs and CBPR because it emphasized the credibility and capacity of CBOs to develop, own, manage, foster, and sustain viable research agendas to address ongoing environmental hazards and related threats to health and quality of life.
Lessons from the Navajo: Assistance with Environmental Data Collection Ensures Cultural Humility and Data Relevance
Authors: deLemos Jamie , Rock Tommy , Brugge Doug , Slagowski Naomi , Manning Thomas , Lewis Johnnye
Published: December 2007

Background: The Navajo Nation suffers from a legacy of environmental pollution from historical uranium mining activities, resulting in adverse public health outcomes and continuous exposure. Objective: Partner with a Navajo graduate student and community members in a field campaign to characterize the spatial distribution and geochemistry of uranium for a multipathway uranium exposure assessment under development by the Diné Network for Environmental Health (DiNEH) project. Methods: Attend community meetings, acquire Navajo language skills, and integrate local knowledge into sampling approach of sediment, water, and vegetation. Results: Navajo participation (1) helped to foster trust in research efforts during community interactions, (2) taught aspects of Navajo culture and language to maintain positive and respectful relations, and (3) conveyed information on Navajo culture that would impact sampling strategies. Conclusions: Community engagement helps to sustain equitable partnerships and aids in culturally appropriate, relevant data collection.
Implementation Evaluation of a Culturally Competent Eye Injury Prevention Program for Citrus Workers in a Florida Migrant Community
Authors: Luque John S , Monaghan Paul , Contreras Ricardo B , August Euna , Baldwin Julie A , Bryant Carol A , McDermott Robert J
Published: December 2007

Background: The Partnership for Citrus Worker Health (PCWH) is a coalition that connects academic institutions, public health agencies, industry and community-based organizations for implementation of an eye safety pilot project with citrus workers using the Camp Health Aide (CHA) model. Objectives: This project was an implementation evaluation of an eye safety curriculum using modeling and peer-to-peer education among Mexican migrant citrus workers in a southwest Florida community to increase positive perceptions toward the use of safety eyewear and reduce occupational eye injuries. Methods: CHAs have been employed and trained in eye safety and health during harvesting seasons since 2004. Field observations, focus group interviews, and written questionnaires assessed program implementation and initial outcomes. Results: There was an increase in positive perceptions toward use of safety eyewear between 2004 and 2005. Evaluation of training suggested ways to improve the curriculum. The modest literacy level of the CHAs necessitated some redesign of the curriculum and its implementation (e.g., introduction of and more reliance on use of training posters). Conclusions: PCWH benefited by extensive documentation of the training and supervision, a pilot project that demonstrated the potential effectiveness of CHAs, and having a well-defined target population of citrus workers (n = 427). Future research can rigorously test the effectiveness of CHAs in reducing eye injuries among citrus workers.
Linking Residents to Long-Term Care Services: First-Year Findings from the Community Connector Program Evaluation
Authors: Felix Holly C , Stewart M. Kathryn , Mays Glen P , Cottoms Naomi , Olson Mary K , Sanderson Herb
Published: December 2007

Background: Long-term care (LTC) is a major health policy issue owing to increasing LTC expenditures and the anticipated growth in the aging population. However, accessing LTC services, especially home- and community-based LTC services, is often difficult. Objectives: This manuscript describes the Community Connector Program, the first known program to use a model in which community health workers (CHWs) help to connect adults in need of LTC to such services. We examine the community–university–government agency partnership created to implement and evaluate the program, summarize the evaluation design, and provide first-year implementation results. Methods: Descriptive statistics were used to characterize persons served and services to which persons were connected. The quasi-experimental evaluation design, which is planned to estimate the program's impact on LTC service utilization and costs within the Arkansas Medicaid program, is described. Results: Community Connectors linked 686 persons (92% >18 years, 80% African American, 58% female) to at least one needed service. Only 39% of adults served needed LTC based on an LTC screening tool. Nearly all (93%) adults in need of LTC had health insurance; 53% had Medicare; 37%, both Medicare and Medicaid; and 11%, Medicaid. Community Connectors referred adults in need of LTC to 68 agencies and helped them to connect to services to address an average of two needs per adult. Conclusions: Preliminary results from the first-year implementation evaluation indicate the program is effective in linking persons to needed LTC, although program refinements were made to improve targeting of intended program recipients.
Music as Erotic Magic in a Renaissance Romance*
Authors: Brooks Jeanice
Published: December 2007

This study examines the musical writings of the occult philosopher Jacques Gohory, particularly his musical additions to his version of book 11 of the serial romanceAmadis de Gaule. Although music and romance were often treated by contemporaries as, at best, trivial occupations for leisure hours, Gohory saw both as potential triggers for beneficial self-transformation: music and romance fully participate in the therapeutic and spiritual goals that motivate his more overtly philosophical and medical works. His use of romance as a vehicle for occult philosophy was an important means of disseminating concepts of music as natural magic beyond intellectual circles into the wider milieu of the French court, where occult understandings of music gained substantial currency by 1600.
Patrician Sages and the Humanist Cynic: Francesco Filelfo and the Ethics of World Citizenship*
Authors: Blanchard W. Scott
Published: December 2007

The fifteenth-century humanist Francesco Filelfo (1398–1481) spent much of the period from 1429 to 1444 involved with Florentine politics, becoming a strong advocate on behalf of the patrician oligarchs, many of whom were exiled in 1434 at the return of Cosimo de’ Medici from eleven months of exile. Filelfo’s works from the period, including his satires, theOratio ad exules,and the consolatory treatise entitledCommentationes Florentinae de exilio,were a response to the Florentine political crisis. Filelfo demonstrates in these works not only a rhetorical and political purpose on behalf of his patrons, but also takes the opportunity to reflect on the notion ofworld citizenship,a philosophical concept derived largely from Stoic and Cynic sources.
“If I could write”: Margherita Datini and Letter Writing, 1385–1410*
Authors: Crabb Ann
Published: December 2007

Margherita Datini’s correspondence with her husband Francesco presents a well-documented case of progress from partial to full literacy. In Margherita’s merchant world, letter writing was a major concern, and her household duties included frequent reports to her absent husband. First, she prided herself on her dictation, and then she turned her attention to reading and writing. A recently discovered autograph letter shows that she was writing at twenty-eight, earlier than previously thought, and she attained full literacy in her mid-thirties. After that, writing no longer seemed a challenge, and she returned to using a scribe.
Marking Time: Astrology, Almanacs, and English Protestantism*
Authors: Chapman Alison A.
Published: December 2007

This essay correlates changes in early modern astrological almanacs with broad changes in early modern English Protestant culture over the sixteenth and seventeenth century. These almanacs show an increasing tendency to be highly specific as to place and time and to suggest that precise times and precise places are given a larger meaning by their relationship to the stars and planets wheeling overhead. By lending a vertical significance to place and time, almanacs run counter to early modern Protestantism, which suggested that place and time have no inherent sacred significance. Thus the rise of the early modern astrological almanac may have been impelled by a desire on the part of early modern men and women to have time and place mean something.
Developing regional clusters in India: The role of national laboratories
Authors: Roy Santanu , Banerjee Parthasarathi
Published: December 2007

This paper sets in perspectives the development of regional industrial clusters in India and discusses issues related to technology transfer from public-funded R&D laboratory system in India, such as the Council of Scientific and Industrial Research (CSIR), to small and medium enterprises
and the impact of such transfers on the development of Indian industrial clusters. This has been done with the help of case studies of technological and managerial intervention from three specific CSIR laboratories. The paper also discusses different aspects of regional characterisation, specialisation
and the role played by these national laboratories and others in trying to resolve the technological, managerial and social problems faced by industrial and artisan clusters.
Enhancing the competitiveness of SMEs through industrial clusters: The Indian experience
Authors: Venkataramanaiah S , Parashar S.P
Published: December 2007

The Indian economy is expected to grow by over 8 per cent per annum until 2020 and can become the second largest in the world, ahead of the United States, by 2050, and the third largest after China and the United States by 2032. The turnaround in manufacturing and other sectors, which
has occurred in the face of increased global competition, is due to improved efficiency following the various policy reforms in recent years. Small and medium enterprises (SMEs) constitute 6 per cent of GDP, 34 per cent of national exports and account for the employment of more than 30 million
people. SMEs have improved their performance and presence through industrial cluster approaches. In this paper, we present the experiences of three auto clusters in three major locations in India. We also highlight some of the important issues that SMEs face and conclude by suggesting suitable
cluster interventions for enhancing competitiveness and sustainability of the SME sector.
Differential Effects of Recombinant Adeno-Associated Virus-Mediated Neuropeptide Y Overexpression in the Hypothalamic Paraventricular Nucleus and Lateral Hypothalamus on Feeding Behavior
Authors: Tiesjema Birgitte , Adan Roger A. H. , Luijendijk Mieneke C. M. , Kalsbeek Andries , la Fleur Susanne E.
Published: December 2007

It is well known that neuropeptide Y (NPY) increases food intake. The hypothalamic paraventricular nucleus (PVN) and the lateral hypothalamus (LH) are both involved in the acute, hyperphagic effects of NPY. Although it is obvious that increased energy intake may lead to obesity, it is less understood which aspects of feeding behavior are affected and whether one or multiple neural sites mediate the effects of long-term increased NPY signaling. By long-term overexpressing NPY in either the PVN or the LH, we uncovered brain site-specific effects of NPY on meal frequency, meal size, and diurnal feeding patterns. In rats injected with adeno-associated virus-NPY in the PVN, increased food intake resulted from an increase in the amount of meals consumed, whereas in rats injected in the LH, increased food intake was attributable to increased meal size. Interestingly, food intake and body weight gain were only temporarily increased in PVN-injected rats, whereas in LH-injected rats hyperphagia and body weight gain remained for the entire 50 d. Moreover, in LH-NPY rats, but not in PVN-NPY rats, diurnal rhythmicity with regard to food intake and body core temperature was lost. These data clearly show that the NPY system differentially regulates energy intake and energy expenditure in the PVN and LH, which together adjust energy balance.
Plasticity of Intrinsic Excitability during Long-Term Depression Is Mediated through mGluR-Dependent Changes inIhin Hippocampal CA1 Pyramidal Neurons
Authors: Brager Darrin H. , Johnston Daniel
Published: December 2007

Bidirectional changes in synaptic strength are the proposed cellular correlate for information storage in the brain. Plasticity of intrinsic excitability, however, may also be critical for regulating the firing of neurons during mnemonic tasks. We demonstrated previously that the induction long-term potentiation was accompanied by a persistent decrease in CA1 pyramidal neuron excitability (Fan et al., 2005). We show here that induction of long-term depression (LTD) by 3 Hz pairing of back-propagating action potentials with Schaffer collateral EPSPs was accompanied by an overall increase in CA1 neuronal excitability. This increase was observed as an increase in the number of action potentials elicited by somatic current injection and was caused by an increase in neuronal input resistance. After LTD, voltage sag during hyperpolarizing current injections and subthreshold resonance frequency were decreased. All changes were blocked by ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride), suggesting that a physiological loss of dendritic h-channels was responsible for the increase in excitability. Furthermore, block of group 1 metabotropic glutamate receptors (mGluRs) or protein kinase C prevented the increase in excitability, whereas the group 1 mGluR agonist DHPG [(RS)-3,5-dihydroxyphenylglycine] mimicked the effects. We conclude that 3 Hz synaptic stimulation downregulatesIhvia activation of group 1 mGluRs and subsequent stimulation of protein kinase C. We propose these changes as part of a homeostatic and bidirectional control mechanism for intrinsic excitability during learning.
Decreased Nociceptive Sensitization in Mice Lacking the Fragile X Mental Retardation Protein: Role of mGluR1/5 and mTOR
Authors: Price Theodore J. , Rashid Md Harunor , Millecamps Magali , Sanoja Raul , Entrena Jose M. , Cervero Fernando
Published: December 2007

Fragile X mental retardation is caused by silencing of the gene (FMR1) that encodes the RNA-binding protein (FMRP) that influences translation in neurons. A prominent feature of the human disorder is self-injurious behavior, suggesting an abnormality in pain processing. Moreover, FMRP regulates group I metabotropic glutamate receptor (mGluR1/5)-dependent plasticity, which is known to contribute to nociceptive sensitization. We demonstrate here, using theFmr1knock-out (KO) mouse, that FMRP plays an important role in pain processing becauseFmr1KO mice showed (1) decreased (∼50%) responses to ongoing nociception (phase 2, formalin test), (2) a 3 week delay in the development of peripheral nerve injury-induced allodynia, and (3) a near absence of wind-up responses in ascending sensory fibers after repetitive C-fiber stimulation. We provide evidence that the behavioral deficits are related to a mGluR1/5- and mammalian target of rapamycin (mTOR)-mediated mechanism because (1) spinal mGluR5 antagonism failed to inhibit the second phase of the formalin test, and we observed a marked reduction in nociceptive response to an intrathecal injection of an mGluR1/5 agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) inFmr1KO mice; (2) peripheral DHPG injection had no effect in KO mice yet evoked thermal hyperalgesia in wild types; and (3) the mTOR inhibitor rapamycin inhibited formalin- and DHPG-induced nociception in wild-type but notFmr1KO mice. These experiments show that translation regulation via FMRP and mTOR is an important feature of nociceptive plasticity. These observations also support the hypothesis that the persistence of self-injurious behavior observed in fragile X mental retardation patients could be related to deficits in nociceptive sensitization.
Disrupted Dentate Granule Cell Chloride Regulation Enhances Synaptic Excitability during Development of Temporal Lobe Epilepsy
Authors: Pathak Hemal R. , Weissinger Florian , Terunuma Miho , Carlson Gregory C. , Hsu Fu-Chun , Moss Stephen J. , Coulter Douglas A.
Published: December 2007

GABAAreceptor-mediated inhibition depends on the maintenance of intracellular Cl−concentration ([Cl−]in) at low levels. In neurons in the developing CNS, [Cl−]inis elevated,EGABAis depolarizing, and GABA consequently is excitatory. Depolarizing GABAergic synaptic responses may be recapitulated in various neuropathological conditions, including epilepsy. In the present study, rat hippocampal dentate granule cells were recorded using gramicidin perforated patch techniques at varying times (1–60 d) after an epileptogenic injury, pilocarpine-induced status epilepticus (STEP). In normal, non-epileptic animals, these strongly inhibited dentate granule cells act as a gate, regulating hippocampal excitation, controlling seizure initiation and/or propagation. For 2 weeks after STEP, we found thatEGABAwas positively shifted in granule cells. This shift inEGABAaltered synaptic integration, increased granule cell excitability, and resulted in compromised “gate” function of the dentate gyrus.EGABArecovered to control values at longer latencies post-STEP (2–8 weeks), when animals had developed epilepsy. During this period of shiftedEGABA, expression of the Cl−extruding K+/Cl−cotransporter, KCC2 was decreased. Application of the KCC2 blocker, furosemide, to control neurons mimickedEGABAshifts evident in granule cells post-STEP. Furthermore, post-STEP and furosemide effects interacted occlusively, both onEGABAin granule cells, and on gatekeeper function of the dentate gyrus. This suggests a shared mechanism, reduced KCC2 function. These findings demonstrate that decreased expression of KCC2 persists for weeks after an epileptogenic injury, reducing inhibitory efficacy and enhancing dentate granule cell excitability. This pathophysiological process may constitute a significant mechanism linking injury to the subsequent development of epilepsy.
Real-time 3-dimensional echocardiography – can there be one more dimension?
Authors: Nemes Attila , Geleijnse Marcel L. , Soliman Osama I.I. , Anwar Ashraf M. , Bosch Johan G. , Krenning Boudewijn J. , Yap Sing-Chien , Vletter Wim B. , McGhie Jackie S. , Forster Tamás , Csanády Miklós , ten Cate Folkert J.
Published: December 2007

A kardiológiai betegek ellátásában a noninvazív vizsgáló módszereknek alapvető jelentőségük van. Elméletileg a szív akkor vizsgálható tökéletesen, ha természetének megfelelően három dimenzióban rögzítjük a szívciklus szerint. A második generációs, immár real-time (vagyis valós idejű) háromdimenziós echokardiográfok elméletileg optimális lehetőséget nyújtanak a cardialis struktúrák háromdimenziós elemzésére. Real-time 3-dimenziós echokardiográfia során pontosan mérhetők a kamrai és pitvari térfogatok, valamint a kamrai izomtömeg. A billentyűk és a congenitalis abnormalitások ‘en-face’ vizsgálhatók. Használhatóságát terheléses protokollok alkalmazása mellett igazolták. A jelen összefoglaló közlemény célja a módszer bemutatása, lehetséges előnyeinek tisztázása a jelenleg még fennálló technológiai korlátok bemutatásával együtt.
Terapia hormonal na menopausa: quando não usar
Authors: Spritzer Poli Mara , Wender Maria Celeste Osório
Published: December 2007

A menopausa corresponde à cessação permanente da menstruação, conseqüente à perda da função folicular ovariana ou à remoção cirúrgica dos ovários. A idade média para ocorrência da menopausa natural gira em torno de 50 anos. A deficiência estrogênica decorrente da menopausa está associada com sintomas vasomotores, atrofia urogenital, declínio cognitivo, assim como a um aumento no risco de doenças crônico-degenerativas, aterosclerose e doença cardiovascular, osteoporose e doença de Alzheimer. A estrogenioterapia permanece sendo o tratamento mais efetivo para o manejo dos sintomas vasomotores e atrofia urogenital. Em mulheres com útero presente, a progesterona natural ou os progestogênios devem ser associados ao tratamento com estradiol para antagonizar os efeitos proliferativos deste hormônio sobre o endométrio e anular o risco de hiperplasia/carcinoma endometrial. Por outro lado, em determinadas condições clínicas, a terapia hormonal não é recomendada ou é mesmo contra-indicada. Neste artigo, focalizamos criticamente essas situações clínicas em que não se deve indicar a terapia hormonal na menopausa.
Melhoramento da crotalária. I - Autocompatibilidade e resistência à murcha de Ceratocystis fimbriata
Authors: Ribeiro Ivan J. A. , Miranda Manoel Albino C. de , Bulisani E. A. , Almeida L. D'Artagnan de , Lovadini L. A. Costa , Sugimori Mauro H. , Paradela Filho O.
Published: December 2007

O presente trabalho foi desenvolvido visando à obtenção de linhagens de Crotalaria juncea autocompatíveis e resistentes à murcha de Ceratocystis fimbriata. Plantios sucessivos de crotalária comum foram efetuados em área altamente infestada pelo patógeno. Em cada ciclo foram selecionadas plantas que chegaram a produzir sementes, sendo estas plantadas no ano seguinte. Após quatro anos, o material resultante foi cruzado com linhagens autocompatíveis, visando reunir o caráter resistência à condição de autocompatibilidade. A geração F1 desse cruzamento foi retrocruzada com pais resistentes e com pais autocompatíveis. As populações assim obtidas foram levadas até a geração F4, sendo que em cada geração eram feitas inoculações e seleção de plantas resistentes e autocompatíveis. A geração F5, com 1.030 plantas, foi selecionada para produção e qualidade de sementes, resultando em 111 plantas com as características desejadas. As linhagens dessas plantas, após inoculação com isolados do fungo, mostraram alta porcentagem de plantas autocompatíveis, com resistência à murcha.
O método tampão SMP para determinação da necessidade de calagem de solos do estado de São Paulo
Authors: Van Raij Bernardo , Cantarella Heitor , Zullo Marco Antônio Teixeira
Published: December 2007

O método tampão SMP de determinação da necessidade de calagem foi estudado em 23 amostras de solos do Estado de São Paulo. A calibração do método foi feita através das necessidades de calagem para valores de pH de 5,5, 6,0 e 6,5 obtidos de curvas de neutralização dos solos com CaCO3. Foram testadas três relações de solução-tampão e solo, optando-se por uma modificação que deu ao método maior sensibilidade para baixas necessidades de calagem, se comparada com a metodologia original. Foi feita a comparação do método SMP com outros critérios de determinação da necessidade de calagem. O método SMP é eficaz para determinar a quantidade de CaCO3 para atingir determinado valor de pH do solo. Tal não acontece com o cálculo baseado na relação entre pH e saturação em bases, que leva a valores muito baixos. O critério Al x 1,5 permite chegar a valores de pH em torno de 5,5. A elevação dos valores de Ca + Mg a 2 ou 3 meq/100cm³ de terra não permite prever o pH a ser obtido no solo, consistindo, deste ponto de vista, em um critério muito inseguro para calcular a necessidade de calagem dos solos.
Comportamento das variedades de algodoeiro IAC 13-1, IAC 16 e IAC 17 em ensaio permanente de adubação com superfosfato simples
Authors: Silva Nelson Machado da , Gridi-Papp Imre L. , Ciá Edivaldo , Carvalho Luiz H. , Hiroce Ruter
Published: December 2007

Visando à avaliação do aproveitamento de nutrientes fornecidos através de sucessivas adubações com superfosfato simples, foi conduzido, durante três anos agrícolas, ensaio permanente de campo em latossolo roxo ácido, de baixa fertilidade, com as variedades paulistas de algodão IAC 13-1, IAC 16 e IAC 17. Adotou-se o esquema de parcelas subdivididas, sendo os tratamentos distribuídos em blocos ao acaso com quatro repetições. As parcelas maiores foram ocupadas pelas doses 0, 225, 450 e 675kg/ha de superfosfato simples, enquanto as subparcelas o foram pelas variedades. A gleba experimental recebeu aplicação de corretivo de acidez antes do primeiro plantio e adubações anuais de nitrogênio e potássio nas doses fixas de 50 a 75kg/ha de N e K2O, respectivamente. Análise de amostra de solo colhida no terceiro ano de estudo revelou sensíveis acréscimos nos teores de fósforo e de cálcio, decorrentes do uso contínuo de superfosfato simples. A adubação concorreu significativamente para aumentar a concentração de cálcio do limbo foliar e diminuir a de potássio; as concentrações de fósforo e de magnésio foram também influenciadas favoravelmente. Constatou-se antagonismo entre cálcio e potássio e entre magnésio e potássio. A variedade IAC 17 apresentou concentrações de N, P, S, Ca e K superiores às demais. O cultivo do algodoeiro no primeiro ano revelou-se antieconômico em função da baixa reação das plantas ao emprego do adubo e às desfavoráveis condições de comercialização do produto. No segundo e terceiro anos de acúmulo de superfosfato simples, os efeitos sobre a produção foram crescentes, o que sugere a conveniência do uso de dosagens maiores do produto em novos ensaios a serem efetuados, e estudos de outros modos de aplicação de adubo. A variedade IAC 17 demonstrou maior capacidade de aproveitamento do superfosfato simples acumulado através dos anos.
Efeitos de métodos de escarificação na germinação de sementes de cinco leguminosas forrageiras
Authors: Almeida Luiz D'Artagnan de , Maeda Jocely A. , Falivene Sônia M. P.
Published: December 2007

Cinco espécies de leguminosas forrageiras, soja-perene (Glycine wightii), siratro (Macroptilium atropurpureum), centrosema (Centrosema pubescens), calopogônio (Calopogonio mucunoides) e cudzu-tropical (Pueraria phaseoloides), foram estudadas quanto ao poder germinativo das sementes, avaliando-se a necessidade de escarificação logo após a colheita e durante o período do armazenamento, através da utilização de ácido sulfúrico concentrado, calor, atrito entre lixas e água quente. Verificou-se ainda a possibilidade de haver uma relação entre coloração do tegumento e porcentagem de sementes duras. Quando não escarificadas, as sementes das cinco espécies apresentaram alta porcentagem de sementes duras, e o repouso não possibilitou a melhoria na germinação, com exceção da centrosema. Todos os métodos de escarificação melhoraram o índice de germinação das sementes, sobressaindo o ácido sulfúrico como o mais eficiente para todas as espécies. O efeito do calor foi bem melhor para cudzu-tropical e, o atrito entre lixas, foi apenas razoável para todas as espécies. A água quente proporcionou bons índices de germinação para siratro e calopogônio, provocando, entretanto, a ocorrência de alta porcentagem de sementes mortas no final do período de armazenamento. Para longos períodos de armazenamento, é preferível, em qualquer caso, fazer a escarificação na época de semeadura, pois haverá menor ocorrência de sementes mortas. Verificou-se ainda que a diferença de coloração nos lotes de sementes não influiu na ocorrência de sementes duras, mas esteve relacionada com a existência de sementes mortas.
Adubação do algodoeiro com micronutrientes e matéria orgânica em solos de cerrado
Authors: Rodrigues Filho Francisco Solano de Oliveira , Sabino Nelson Paulieri
Published: December 2007

Ensaios de campo foram conduzidos no Estado de São Paulo, por dois anos agrícolas, 1973/74 e 1974/75, em solos de cerrado, classificados como Latossolo Vermelho-Amarelo fase arenosa, no município de Aguaí, e Podzólico Vermelho-Amarelo variação Laras, no de Ibitiruna, para estudar a aplicação de micronutrientes (zinco, cobre e manganês) e matéria orgânica (esterco de galinha) na cultura do algodoeiro. Não foram verificados efeitos significativos pela aplicação de micronutrientes, embora fornecimentos isolados dos elementos, em associação com uma adubação básica NPK, tenham proporcionado aumentos de 18, 30 e 35% na produção, respectivamente para zinco, cobre e manganês. O esterco de galinha provocou efeito significativo sobre a produção, com aumentos de até 44%, quando utilizado na dose de 800kg/ha. Sua aplicação não associada à adubação mineral básica NPK, proporcionou produção de algodão em caroço semelhante ao tratamento sem adubo, no ano agrícola 1974/75. Não foi constatado efeito significativo dos micronutrientes e da matéria orgânica, quer sobre as características agronômicas, quer sobre as propriedades tecnológicas da fibra.
Fontes de resistência a Scrobipalpula absoluta (Meyrick, 1917) em tomateiro
Authors: Lourenção André Luiz , Nagai Hiroshi , Zullo Marco Antonio Teixeira
Published: December 2007

Com o objetivo de encontrar fontes de resistência à traça Scrobipalpula absoluta (Meyr.), em tomateiro, foram avaliados diversos genótipos das espécies Lycopersicon esculentum, L. pimpinellifolium e L. peruvianum. Em triagem inicial em casa de vegetação, as introduções NAV 29 e NAV 115, pertencentes a L. peruvianum, destacaram-se como os genótipos mais resistentes a esse inseto, apresentando a menor perda de área foliar. Uma linhagem de L. pimpinellifolium, NAV 98, mostrou-se menos atacada nos ponteiros que os genótipos de L. esculentum. Uma mistura de pólen de NAV 29 e NAV 115 foi utilizada para polinização de plantas dessas duas introduções, e as sementes obtidas desse processo denominaram-se NAV 29/115. A seguir, foi feito experimento em casa de vegetação envolvendo NAV 29/115, NAV 98, 'Rio Grande' e 'Pavesetter', sendo esses dois cultivares de L. esculentum de crescimento determinado. A infestação foi artificial, através de plantas fortemente infestadas pela traça e colocadas entre as plantas do experimento. Avaliações feitas periodicamente estimando visualmente a porcentagem de área foliar consumida pelas lagartas de S. absoluta, evidenciaram alta resistência de NAV 29/115 em relação aos demais materiais. O presente trabalho mostra que NAV 29, NAV 115 e NAV 29/115, genótipos de L. peruvianum, constituem promissoras fontes de resistência à traça S. absoluta.