bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-time asymptotics of heat kernels for a class of hypoelliptic operators
Authors: Brockett R. W. , Mansouri A.
Published: December 2009

We compute the short-time asymptotics of heat kernels for a family of hypoelliptic operators, and
we relate these to the value function of an associated variational problem previously investigated
in the control theory literature. These heat kernels generalize to the noncontact case a heat
kernel that has been previously obtained for the contact hypoelliptic Laplacian defined on the
Heisenberg group.
A combinatorial approach to functorial quantum sl k knot invariants
Authors: Mazorchuk Volodymyr , Stroppel Catharina
Published: December 2009

This paper contains a categorification of the ${\frak sl}(k)$ link invariant
using parabolic singular blocks of category ${\cal{O}}$. Our approach is
intended to be as elementary as possible, providing essentially
combinatorial arguments for the main results of Sussan. The justification
that our combinatorial arguments and steps are correct uses
non-combinatorial geometric and representation theoretic results (e.g., the
Kazhdan-Lusztig and Soergel's theorems). We take these results as granted
and use them like axioms (called {\it Facts\/} in the text).
We first construct an exact functor valued invariant of webs or ``special''
trivalent graphs labelled with $1, 2, k-1, k$ satisfying the MOY relations.
Afterwards we extend it to the ${\frak sl}(k)$-invariant of links by
passing to the derived categories. The approach of Khovanov using foams
appears naturally in this context. More generally, we expect that our
approach provides a representation theoretic interpretation of the ${\frak
sl}(k)$-homology, based on foams and the Kapustin-Li formula, from Mackaay,
Stosic, and Vaz. Conjecturally this implies that the Khovanov-Rozansky link
homology is obtained from our invariant by restriction.
Arithmetic and differential Swan conductors of rank one representations with finite local monodromy
Authors: Chiarellotto Bruno , Pulita Andrea
Published: December 2009

We consider a complete discrete valuation field of characteristic $p$, with possibly
nonperfect residue field. Let ${\rm V}$ be a rank one continuous representation of its
absolute Galois group with finite local monodromy. We will prove that the {\it
arithmetic Swan conductor\/} of ${\rm V}$ (defined after K.~Kato, which fits in the more
general theory of Abbes-Saito) coincides with the {\it differential Swan conductor\/}
of the associated differential module ${\rm D}^{\dag}({\rm V})$ defined by K.~Kedlaya. This
construction is a generalization to the nonperfect residue case of the Fontaine's
formalism as presented in the work of N.~Tsuzuki. Our method of proof will allow us to
give a new interpretation of the refined Swan conductor.
Global existence for energy critical waves in 3-D domains: Neumann boundary conditions
Authors: Burq Nicolas , Planchon Fabrice
Published: December 2009

We prove that the defocusing quintic wave equation,
with Neumann boundary conditions, is globally well-posed on
$H^1_N(\Omega) \times L^2( \Omega)$ for any smooth (compact) domain
$\Omega \subset {\Bbb R}^3$. The proof relies on one hand on $L^p$
estimates for the spectral projector, and on the other hand on
a precise analysis of the boundary value problem, which turns out to
be much more delicate than in the case of Dirichlet boundary
conditions.
The Horn conjecture for sums of compact selfadjoint operators
Authors: Bercovici H. , Li W. S. , Timotin D.
Published: December 2009

We determine the possible nonzero eigenvalues of compact selfadjoint
operators $A$, $B^{(1)}$, $B^{(2)}$, $\dots$, $B^{(m)}$ with the property
that $A=B^{(1)}+B^{(2)}+\cdots+B^{(m)}$. When all these operators are
positive, the eigenvalues were known to be subject to certain inequalities
which extend Horn's inequalities from the finite-dimensional case when
$m=2$. We find the proper extension of the Horn inequalities and show that
they, along with their reverse analogues, provide a complete
characterization. Our results also allow us to discuss the more general
situation where only some of the eigenvalues of the operators $A$ and
$B^{(k)}$ are specified. A special case is the requirement that
$B^{(1)}+B^{(2)}+\cdots+B^{(m)}$ be positive of rank at most $\rho\ge1$.
Asymptotically unitary equivalence and asymptotically inner automorphisms
Authors: Lin Huaxin
Published: December 2009

Let $C$ be a unital AH-algebra and let $A$ be a unital separable
simple $C^*$-algebra with tracial rank zero. Suppose that $\phi_1, \phi_2\colon \
C\to A$ are two unital monomorphisms. We show that there is a
continuous path of unitaries $\{u_t\colon \ t\in [0, \infty)\}$ of $A$
such that
$$
\lim_{t\to\infty}u_t^*\phi_1(a)u_t=\phi_2(a)\quad\hbox{\rm for all}\quad a\in C
$$
if and only if $[\phi_1]=[\phi_2]$ in $KK(C,A),$ $\tau\circ
\phi_1=\tau\circ \phi_2$ for all $\tau\in T(A)$ and the rotation
map ${\tilde\eta}_{\phi_1,\phi_2}$ associated with $\phi_1$ and
$\phi_2$ is zero. In particular, an automorphism $\alpha$ on a
unital separable simple $C^*$-algebra $A$ in ${\cal N}$ with tracial rank
zero is asymptotically inner if and only if
$$
[\alpha]=[{\rm id}_A]\quad{\rm in}\quad KK(A,A)
$$
and the rotation map ${\tilde\eta}_{\phi_1, \phi_2}$ is zero.

Let $A$ be a unital AH-algebra (not necessarily simple) and let
$\alpha\in Aut(A)$ be an automorphism. As an application, we show
that the associated crossed product $A\rtimes_{\alpha}{\Bbb Z}$ can be
embedded into a unital simple AF-algebra if and only if $A$ admits
a strictly positive $\alpha$-invariant tracial state.
Singularities of solutions to the Schrödinger equation on scattering manifold
Authors: Ito Kenichi , Nakamura Shu
Published: December 2009

In this paper we study microlocal singularities of solutions to Schr\"odinger equations on
scattering manifolds, i.e., noncompact Riemannian manifolds with asymptotically conic ends. We
characterize the wave front set of the solutions in terms of the initial condition and the
classical scattering maps under the nontrapping condition. Our result is closely related to a
recent work by Hassell and Wunsch, though our model is more general and the method, which relies
heavily on scattering theoretical ideas, is simple and quite different. In particular, we use an
Egorov-type argument in the standard pseudodifferential symbol classes, and avoid using Legendre
distributions. In the proof, we employ a microlocal smoothing property in terms of the {\it
radially homogenous wave front set}, which is more precise than the preceding results.
Moving codimension-one subvarieties over finite fields
Authors: Totaro Burt
Published: December 2009

We give the first examples of nef line bundles on smooth projective
varieties over finite fields which are not semi-ample. More concretely, we
find smooth curves on smooth projective surfaces over finite fields such
that the normal bundle has degree zero, but no positive multiple of the
curve moves in a family of disjoint curves. This answers questions by Keel
and Mumford. The proof uses an obstruction theory, in the spirit of homotopy
theory, which links the infinitely many obstructions to moving higher and
higher multiples of a given codimension-one subvariety. On 3-folds over a
finite field, we find nef and big line bundles which are not semi-ample.
Finally, we reprove some of the known positive results about semi-ampleness
over finite fields.
What's the Deal with Soundtrack Albums?: Metal Music and the Customized Aesthetics of Contemporary Horror
Authors: Tompkins Joseph
Published: December 2009

This essay argues that film music functions not only as a cross-promotional medium for marketing movies and licensed recordings, but also as a key site for effectively managing and containing processes of consumption. Heavy metal music is deployed in horror films like Freddy vs. Jason (Ronny Yu, 2003) to interpellate particular niche audiences and taste communities. Thus, soundtrack albums reveal a fundamental assumption within media firms that a manageable relationship between niche formats and consumer tastes exists to be exploited.
"Noble and Uplifting and Boring as Hell": Asian American Film and Video, 1971–1982
Authors: Okada Jun
Published: December 2009

Asian American film and video evolved out of the civil rights and ethnic studies movements, sharing with them a fundamental ideology of social change. However, a closer examination of its institutional history shows how this tradition conflicted with an equally important and at times contradictory discourse of aesthetics and form.
Undesirable Bodies and Desirable Labor: Documenting the Globalization and Digitization of Transnational American Dreams in Indian Call Centers
Authors: Hudson Dale
Published: December 2009

With their emphasis on digitally mediated performance and illusion, Indian call centers are an unruly subject for realist modes of documentary. This article rethinks documentary practices by comparing documentaries that sustain globalization's illusions of interface and access to the American dream with documentaries that disrupt these illusions.
Avant-Garde Re-Enactment: World Mirror Cinema, Decasia , and The Heart of the World
Authors: Pierson Michele
Published: December 2009

This essay looks at how a number of avant-garde films that work with cinematic images of the past involve spectators in the imaginative creation of historical worlds. These films are re-enactments, not in the sense of offering re-creations of specific historical events, but in the sense of involving spectators in an experience that offers them a feeling for the past.
Looking for Vito
Authors: Schiavi Michael
Published: December 2009

What is the purpose of looking for Vito Russo in 2009? Though dead for nineteen years, and though almost universally dismissed in current queer film theory, Russo and his Celluloid Closet (1981; rev. 1987) remain indispensable to our reading of gender and sexuality on screen.
Modalities of Belief in Ancient Christian Debate
Authors: McCarthy Michael C.
Published: December 2009

While central to most aspects of early Christianity, the concept of belief has itself received little attention. In this essay, the author challenges a common distinction between belief and practice and argues that belief itself functions, not simply as a private mental act, but as a complex social performance. Recent anthropological treatments confirm what Augustine, in De utilitate credendi , suggests: believing depends crucially on some form of recognition from one's fellows. Attention to this dynamic allows for a more amplified conception of belief, which stresses the continuity between thought and action, admits of highly textured "modalities" of believing, and helps explain the behavior of multiple sides in theological debates. As a case in point, the early Pelagian controversy illustrates how agents employ various strategies of accommodation—even at the risk of appearing inconsistent or duplicitous—in order to maintain the very ground of belief, i.e., the apparent expectation of a larger body with whom one is in consensus.
Apolytrosis as Ritual and Sacrament: Determining a Ritual Context for Death in Second-Century Marcosian Valentinianism
Authors: Lewis Nicola Denzey
Published: December 2009

Irenaeus of Lyons reports that a second-century Valentinian group, the Marcosians, developed a ritual system that included a sacrament performed for an individual at the point of death. The rite helped to "establish" the individual in the higher celestial realms. Using comparanda from various ancient sources, this paper examines our extant evidence for early Christian death rites. It asserts that the Valentinian death sacrament precedes the development of a similar Catholic rite by nearly a thousand years, thus attesting to the sophistication of Valentinian ritual systems distinct from those of the nascent orthodox church.
Reclaiming Paul?: Reconfiguration as Reclamation in 3 Corinthians
Authors: White Benjamin L.
Published: December 2009

This article pursues an alternative approach to situating the historical circumstances and rhetorical strategies of the author of 3 Corinthians . Whereas most scholarship on 3 Corinthians has set out to ascertain the specific opponents lurking behind the polemic of the text (Simon Magus, Saturnilus, Marcion, Valentinus, etc.), I believe that this task is futile and that a close reading of the "Paul" constructed by the text's author pays more fruitful dividends in situating the text. Specifically, I will argue that 3 Corinthians is a late second-century proto-orthodox invocation of the "Pastoral" Paul (i.e. the Paul of the Pastoral Epistles), who stands as the defender of apostolic teaching in the face of "deviant views" of a generally "gnostic" variety. Its closest rhetorical analogue is Irenaeus of Lyons. Both the author of 3 Corinthians and Irenaeus participate in a broad, late second-century move to reclaim Paul from the "heretics." Yet in each of these cases, the reclamation projects involve a tacit reconfiguration of the "historical" Paul. Among other things, Paul ironically becomes a defender of σάρξ.
Jewish Women's Resistance to Christianity in the Early Fifth Century: The Account of Severus, Bishop of Minorca
Authors: Kraemer Ross S.
Published: December 2009

The Letter of Severus of Minorca on the Conversion of the Jews , narrating the conversion of the entire Jewish population of the island in the space of one week in February, 418 C.E. has been taken by some scholars as a reliable account of Jewish women's principled resistance to Christianity, based on the author's representation of women as the last to convert. The author deploys Jewish women and gender relations for various rhetorical purposes that call into question the historicity of these and other details of the Letter . Severus feminizes Jews and presents their gender relations as disordered: only when they become Christians do their gender relations become properly ordered. Women's initial refusal of Christ exemplifies Jewish stubbornness and wifely insubordination. Had the women converted before their husbands, their conversions would not have served the author's argument that Christ makes Jewish women appropriately submissive and accepting of (Christian) male authority. Further, Severus's subsequent re-masculination of Jewish men once they become Christian may relate to various power contests that underlie the text.
Thinking with Soul: Psychē and Psychikos in the Construction of Early Christian Identities
Authors: Reis David M.
Published: December 2009

Early Christian writers devised numerous rhetorical strategies to clarify their perceptions of Christianity and to distinguish the followers of Jesus from various "others." Yet identity theorists have noticed that the self is not a "fixed" or static category, but rather one that is always under negotiation and (re) examination. Moreover, embedded within arguments distinguishing "us" from "them" are claims to power and knowledge. Drawing upon these insights, this essay examines how the concept of the soul, which had a long history of use in philosophic discussions on selfhood, became a useful tool to establish early Christian identities and marginalize opponents. Whether understood as a metaphor or as a "real" entity, psychē and its adjectival form psychikos became discursive "markers" in early Christian polemic or apologetic, enabling writers to carve out a sense of self and to establish a place for Christians on the social map of the Greco-Roman world.
Influencing the Now and Future Faculty: Retooling Information Literacy
Authors: Pierce Deborah L.
Published: December 2009

After more than two decades of attempting to make the shift from bibliographic instruction to information literacy, with many successes and a growing body of literature, librarians still face challenges in providing the best educational opportunities for faculty and students. One possible avenue to help us face these challenges is to expend more energy on advocacy and faculty training. This article details a project that trained twenty-nine prospective faculty members in information literacy concepts and practices. In collaboration with a music faculty member teaching a graduate-level course, Teaching Music in Higher Education, the librarian was able to present a session on Information Literacy in the Music Curriculum: Teaching in the Information Age. Since the course was designed to assist graduate students—several who were already teaching their own courses—in making the transition to becoming music faculty, the presentation was advantageously placed to positively affect current and future faculty. Also included is a list of faculty training resources along with suggestions for furthering information literacy advocacy in the field of music.
Librarian in the Classroom: An Embedded Approach to Music Information Literacy for First-Year Undergraduates
Authors: Beutter Manus Sara J.
Published: December 2009

How do you foster the development of foundational research skills in first-year undergraduate music students? This was the dilemma facing Vanderbilt University music librarians and faculty. Although first-year students take an introductory survey course in music literature intended to prepare them for the more demanding courses in the music history and literature core, they were not acquiring the basic information-literacy skills required to successfully complete research papers and assignments. A solution to this problem was to implement a four-semester integrated music information-literacy program that emphasized library instruction for first-year students. To promote the integral role of the library in student learning, the author embedded herself in all three sections of the initial survey course for first-year students. By attending all class meetings, teaching in-class information-literacy sessions, and evaluating assignments, students came to view the author as trusted partner in their educational process. The author details her experiences as an embedded librarian, examining the benefits and challenges of providing instruction to first-year students in this setting. The collaborative process between faculty and librarian in designing the information-literacy components is emphasized, and the tools used to evaluate student progress towards desired music information-literacy outcomes is shared. Also discussed is the importance of regular assessment of the information-literacy program, a process that resulted in revisions that improved the program.
Circumscribed Agency: The Relevance of Standardized College Entrance Exams for Low SES High School Students
Authors: Deil-Amen Regina , LaShawn Tevis Tenisha
Published: December 2009

The authors interviewed Black and Latino students from five high-poverty high schools as they attempted to make the transition into college. Their ability to exert individual agency with regard to their entrance exams and their college transition was circumscribed by the messages and behavioral norms that dominated their low-performing high school context. Students preserved their sense of academic competence, yet they drastically misestimated the relevance of their scores while remaining uninformed about their level of college readiness or how to improve it. The framework for analysis comes from three theories: college choice process, cultural capital, and self-efficacy.
Revisiting the Efficacy of Postsecondary Remediation: The Moderating Effects of Depth/Breadth of Deficiency
Authors: Bahr Peter Riley
Published: December 2009

Postsecondary remediation is an important and highly contentious issue that has received comparatively little comprehensive attention with respect to evaluating its effectiveness. This study addresses two relatively unexplored aspects of remedial efficacy: the moderating effects of depth and breadth of underpreparation. I find that, regardless of the depth or breadth of students' initial deficiencies, students who achieve college-level competency in English and math generally exhibit similar levels of attainment. This finding supports the efficacy of remediation even for students who face the greatest deficiencies in English or math and those who have dual deficiencies in both English and math.
They Need Help: Transfer Students from Four-Year to Four-Year Institutions
Authors: Li Dai
Published: December 2009

This study examines the bachelor's degree attainment among students who first matriculate in four-year institutions but who then transfer to other four-year institutions. It constitutes a contribution to the research that has primarily studied transferring students who start at two-year colleges. This study uses Heckman's two-step model to correct the sample selection bias. The major finding of this study is that transfer students, especially those with broken enrollment, have a much lower probability of bachelor's degree attainment than students with unbroken enrollment. Possible policies to improve the efficiency of four-to-four transfer are also discussed.
State Dream Acts: The Effect of In-State Resident Tuition Policies and Undocumented Latino Students
Authors: Flores Stella M.
Published: December 2009

This study examines the effect of in-state resident tuition legislation across the United States on the college enrollment odds of individuals likely to be undocumented Latino immigrants. The study employs a differences-indifferences strategy using data from the Current Population Survey's Merged Outgoing Rotation Groups. Foreign-born noncitizen Latinos living in states with a tuition policy were 1.54 times more likely to have enrolled in college after the policy's implementation than similar students in states without such legislation. Results are particular to Latino foreign-born noncitizens and not other minority groups with U.S. citizenship, including U.S.-born and naturalized Latinos.
Measuring Globalization's Influence on the Cultural Landscape: Spatial Succession in the Plaza of Ponce, Puerto Rico
Authors: Tillman Benjamin F.
Published: December 2009

Los geógrafos generalmente ven las plazas y la arquitectura que las rodea como uno de los aspectos más tradicionales y conservadores del paisaje cultural latinoamericano. Sin embargo, la plaza latinoamericana se está americanizando debido a los crecientes intercambios internacionales económicos y culturales resultantes de la globalización. Este estudio reporta los cambios en los tipos de negocio localizados adyacentes a la Plaza Ponce, Puerto Rico desde 1907 hasta 2000. Un estudio cuidadoso de la utilización histórica del terreno en la Plaza Ponce demuestra que, los bancos, las cadenas de comida rápida y las tiendas de ropa multinacionales, están reemplazando a los establecimientos de negocio locales. La sucesión espacial se usa como un marco conceptual para examinar el cambio a través del tiempo en la propiedad y función de los edificios ubicados junto a la plaza. Registros de impuestos municipales son usados como una fuente de datos para encontrar el tipo y tasa de cambio a través de varias décadas. Los datos revelan que en 1907 había un solo negocio internacional ubicado adyacente a la plaza. Para el año 2000, siete de los treinta y dos lotes que miran hacia la plaza estaban ocupados por tiendas de cadenas internacionales, y unos nueve lotes adicionales contenían negocios locales con nombres ingleses. El cambio mas rápido ocurrió entre 1980 y 2000. Los resultados de esta in-vestigación indican cambios que pudieran ocurrir con el tiempo en plazas por toda Latinoamérica, ya que históricamente sitios distintos se van haciendo cada vez más similares en su apariencia externa debido a la globalización.
Gated Communities and Housing Projects: The Control of Public Space in San Juan
Authors: García-Ellín Juan C.
Published: December 2009

Este artículo estudia dos maneras específicas en las que están creadas y reguladas las urbanizaciones cerradas con acceso controlado en Puerto Rico. A través de una serie de políticas públicas restrictivas de planificación urbana, el acceso a espacios que se consideraban públicos fue transformado en maneras que afectan el flujo de personas en las áreas urbanas, particularmente en el área metropolitana de San Juan. Esas políticas y particularidades en la construcción de comunidades cerradas en Puerto Rico, así como los patrones de privatización de los espacios públicos en la isla, serán analizadas. Una interpretación de cómo la concepción de los espacios públicos y privados explican estas políticas en un entorno caribeño y sus efectos en la polarizaron social, será parte de la discusión. Los diferentes efectos que estas políticas de planificación tienen en los espacios ocupados por sectores de mas bajos recursos de la población serán comparados con los efectos en personas en las clases medias y mas altas.
Neighborhood Characteristics and Housing Values within the San Juan, MSA, Puerto Rico
Authors: Díaz-Garayúa José R.
Published: December 2009

Este estudio utiliza el método tradicional de regresión global de mínimos cuadrados ordinarios (OLS) y una forma de regresión local, Regresión Ponderada Geográficamente (GWR), para examinar la influencia de las características del vecindario en los valores de las casas a través de San Juan, Puerto Rico MSA y discute la importancia y resultados de los efectos del vecindario en los valores de las casas. Además, desagrupa la influencia de la presencia de grupos nacionales, tales como cubanos y dominicanos, en vez de agruparlos en el grupo monolítico de "Hispanos". Ha sido una práctica común en la literatura el agrupar a nacionalidades bastante diversas, tales como mexicanos, cubanos, puertorriqueños y dominicanos en un simple grupo monolítico etiquetado "Hispanos". El uso de GWR ayuda a identificar los efectos del vecindario porque incorpora relaciones geográficas locales (o las excepciones) de las características del vecindario y de los valores de las casas que ocurren a través del área de estudio destacando la importancia del contexto.
Cassava and Carrying Capacity in Aboriginal Puerto Rico: Revisiting the Taino Downfall at Conquest
Authors: Watlington Francisco
Published: December 2009

¿Cuantos aborígenes vivían en el viejo Borikén (Puerto Rico moderno) al principio de la conquista española? Esta pregunta ha levantado mucha controversia, tanto por la falta de información de primera mano, como por los distintos enfoques usados por practicantes de diferentes disciplinas académicas. Sin embargo, fuentes secundarias de información hacen posible desarrollar un modelo heurístico de la población pasada, basado en el concepto geográfico de "capacidad de carga poblacional". La evaluación de múltiples evidencias disponibles sugiere que el Puerto Rico aborigen era un ecúmeno excepcionalmente denso con una base de subsistencia geográfica al borde del colapso por el agotamiento de los recursos cuando la intrusión española los llevo más allá de sus límites.
Big Boxes, Mega Stores, and Category Killers Overseas: The Emerging Geography of North American Chain Stores (NACS) in Puerto Rico
Authors: Guilbe Carlos J.
Published: December 2009

Las cadenas de tiendas de Norteamérica (NACS)se han estado moviendo a mercados internacionales como parte de su expansión corporativa en una economía globalizada. Puerto Rico, como un sitio central del Caribe, se está convirtiendo en un mercado atractivo. La llegada de estos grandes minoristas coincide con la implementación de prácticas neoliberales en la isla. Nuevos minoristas como Wal-Mart han estado desafiando a otros minoristas establecidos como K-Mart. La competencia entre estos dos gigantes se ha ido haciendo internacional. Ambos mega-minoristas están generando niveles de competencia y estrategias geográficas similares a las de los Estados Unidos continentales. Otros grandes minoristas como Sears, JCPenney, Home Depot, COSTCO y Sam's también están intensificando su presencia, afectando a los pequeños y medianos minoristas y reestructurando el patrón general de utilización de tierras en la isla. En los últimos 15 años, Puerto Rico se ha convertido en un importante prototipo regional que se pudiera difundir a importantes áreas urbanas de América Latina en el futuro cercano.
Bone turnover markers and prediction of fracture: A prospective follow-up study of 1040 elderly women for a mean of 9 years
Authors: Ivaska Kaisa K , Gerdhem Paul , Väänänen H Kalervo , Åkesson Kristina , Obrant Karl J
Published: December 2009

Osteoporosis is characterized by compromised bone mass and strength, predisposing to an increased risk of fracture. Increased bone metabolism has been suggested to be a risk factor for fracture. The aim of this study was to evaluate whether baseline bone turnover markers are associated with long-term incidence of fracture in a population-based sample of 1040 women who were 75 years old (Malmö OPRA study). Seven bone markers (S-TRACP5b, S-CTX-I, S-OC[1–49], S-TotalOC, S-cOC, S-boneALP, and urinary osteocalcin) were measured at baseline and 1-year follow-up visit. During the mean follow-up of 9.0 years (range 7.4–10.9), 363 women sustained at least one fracture of any type, including 116 hip fractures and 103 clinical vertebral fractures. High S-TRACP5b and S-CTX-I levels were associated with increased risk of any fracture with hazard ratios [HRs (95% confidence interval)] of 1.16 (1.04–1.29) and 1.13 (1.01–1.27) per SD increase, respectively. They also were associated with increased risk of clinical vertebral fracture with HRs of 1.22 (1.01–1.48) and 1.32 (1.05–1.67), respectively. Markers were not associated with risk for hip fracture. Results were similar when we used resorption markers, including urinary osteocalcin, measured at the 1-year visit or an average of the two measurements. The HRs were highest for any fracture in the beginning of the follow-up period, 2.5 years from baseline. For vertebral fractures, the association was more pronounced and lasted for a longer period of time, at least for 5 years. In conclusion, elevated levels of S-TRACP5b, S-CTX-I, and urinary osteocalcin are associated with increased fracture risk for up to a decade in elderly women. © 2010 American Society for Bone and Mineral Research
BMP-2 and TGF-β stimulate expression of β1,3-glucuronosyl transferase 1 (GlcAT-1) in nucleus pulposus cells through AP1, TonEBP, and Sp1: Role of MAPKs
Authors: Hiyama Akihiko , Gogate Shilpa S , Gajghate Sachin , Mochida Joji , Shapiro Irving M , Risbud Makarand V
Published: December 2009

The goal of the study was to investigate bone morphogenetic protein 2 (BMP-2) and transforming growth factor β (TGF-β) control of the expression of β1,3-glucuronosyl transferase 1 (GlcAT-1), an important regulator of chondroitin sulfate synthesis in cells of the nucleus pulposus. Treatment with both growth factors resulted in induction of GlcAT-1 expression and promoter activity. Deletion analysis indicated that promoter constructs lacking AP1 and TonE sites were unresponsive to growth factor treatment. Experiments using dominant-negative proteins showed that these transcription factors along with Sp1 were required for induction of GlcAT-1 promoter activity. Moreover, when either AP1 or TonE binding sites were mutated, induction was suppressed. Both BMP-2 and TGF-β increased c-Jun and TonEBP expression and phosphorylation of transactivation domains. We investigated the role of the mitogen-activated protein kinase (MAPK) signaling pathway following growth factor treatment; a robust and transient activation of ERK1/2, p38, and JNK was noted. Treatment with MAPK inhibitors blocked BMP-2- and TGF-β-induced AP1 reporter function, GlcAT-1 expression, and GAG accumulation. We found that DN-ERK1 but not DN-ERK2 resulted in suppression of growth factor–mediated induction of GlcAT-1 promoter activity; we also showed that p38δ was important in GlcAT-1 activation. Results of these studies demonstrate that BMP-2 and TGF-β regulate GlcAT-1 expression in nucleus pulposus cells through a signaling network comprising MAPK, AP1, Sp1, and TonEBP. It is concluded that by controlling both GAG and aggrecan synthesis, these growth factors positively influence disk cell function. © 2010 American Society for Bone and Mineral Research
A new FSHβ mutation in a 29-year-old woman with primary amenorrhea and isolated FSH deficiency: functional characterization and ovarian response to human recombinant FSH
Authors: Kottler Marie-Laure , Chou Yen-Yin , Chabre Olivier , Richard Nicolas , Polge Camille , Brailly-Tabard Sylvie , Chanson Philippe , Guiochon-Mantel Anne , Huhtaniemi Ilpo , Young Jacques
Published: December 2009

Context

Mutations of the FSHβ gene, causing in women isolated FSH deficiency and hypogonadism, are very rare and only a few have been described.

Objective

To describe the phenotype and response to recombinant human (rh) FSH of a female patient with a novel homozygous loss-of-function mutation of FSHβ, and to characterize in vitro the molecular mechanisms responsible for the FSH inactivation.

Patient

A 29-year-old woman with primary amenorrhea and impaired pubertal development associated with isolated FSH deficiency.

Methods and results

Sequencing of the FSHβ gene revealed a homozygous 1 bp (G) deletion at codon 79 (c.289delG) of exon 3 which produced a frameshift at codon 79 (A79fs108X) and a premature stop codon at codon 109. The wild-type and mutant FSHβ cDNAs inserted into expression vector were cotransfected into Chinese hamster ovary cells with the α-subunit. Wild-type FSH was readily detectable in culture medium, whereas no mutant FSH was detectable by either immunoassay or in vitro bioassay. Mutant FSHβ protein could not be detected in western blot.

In response to a 15-day treatment with rhFSH, sonography revealed multifollicular development in the ovaries. Circulating levels of estradiol and inhibin B were dramatically increased, whereas anti-Mullerian hormone decreased. Serum LH first decreased and then increased, inducing multiovulation associated with supraphysiologic progesterone and inhibin A levels.

Conclusion

A novel FSHβ mutation was detected in a hypogonadal woman. rhFSH was effective in ovulation induction in the patient but with signs of ovarian hyperstimulation. The high pretreatment LH levels could contribute to this excessive ovarian response to rhFSH.
Gene expression of PPARγ and PGC-1α in human omental and subcutaneous adipose tissues is related to insulin resistance markers and mediates beneficial effects of physical training
Authors: Ruschke Karen , Fishbein Lauren , Dietrich Arne , Klöting Nora , Tönjes Anke , Oberbach Andreas , Fasshauer Mathias , Jenkner Jost , Schön Michael R , Stumvoll Michael , Blüher Matthias , Mantzoros Christos S
Published: December 2009

Objective

Obesity and type 2 diabetes (T2D) are reaching epidemic proportions in Western societies, and they contribute to substantial morbidity and mortality. The peroxisome proliferator-activated receptor γ (PPARγ) and PPARγ coactivator-1α (PGC-1α) system plays an important role in the regulation of efficient energy utilization and oxidative phosphorylation, both of which are decreased in obesity and insulin resistance.

Design and methods

We measured the metabolic parameters and the expression of PPARγ and PGC-1α mRNA using quantitative real-time PCR in omental and subcutaneous (SC) adipose tissues in an observational study of 153 individuals as well as in SC fat and skeletal muscle in an interventional study of 60 subjects (20 each with normal glucose tolerance, impaired glucose tolerance, and T2D) before and after intensive physical training for 4 weeks.

Results

PPARγ and PGC-1α mRNA expression in both fat depots as well as in skeletal muscle is associated with markers of insulin resistance and cardiovascular risk. PGC-1α mRNA expression is significantly higher in SC fat than in omental fat, whereas PPARγ mRNA expression is not significantly different between these fat depots. Skeletal muscle and SC fat PPARγ and PGC-1α mRNA expression increased significantly in response to physical training.

Conclusions

Gene expression of PPARγ and PGC-1α in human adipose tissue is related to markers of insulin resistance and cardiovascular risk. Increased muscle and adipose tissue PPARγ and PGC-1α expression in response to physical training may mediate the beneficial effects of exercise on insulin sensitivity.
Retrograde tracing of spinal cord connections to the cervix with pregnancy in mice
Authors: Kirby Michael A , Groves Mary M , Yellon Steven M
Published: December 2009

In contrast to the uterus, the cervix is well innervated during pregnancy and the density of nerve fibers increases before birth. To assess neural connections between the cervix and the spinal cord, the cervix of pregnant mice was injected with the trans-synaptic retrograde neural tract tracer pseudorabies virus (PRV). After 5 days, the virus was present in nerve cells and fibers in specific areas of the sensory, autonomic, and motor subdivisions of the thoracolumbar spinal cord. In nonpregnant controls, the virus was predominantly distributed in laminae I–III in the dorsal gray sensory areas with the heaviest label in the substantia gelatinosa compared with the autonomic or motor areas. Labeled cells and processes were sparse in other regions, except for a prominent cluster in the intermediolateral column (lamina VII). Photomicrographs of spinal cord sections were digitized, and the total area with the virus was estimated. Compared with nonpregnant controls, the area with PRV was significantly decreased in all the spinal cord subdivisions in pregnant mice except in the intermediolateral column. However, areas with the virus were equivalent in mice injected with PRV at 4 days or 1 day before birth. These findings suggest that the predominant innervation of the murine cervix is from the sensory regions of the thoracolumbar spinal cord, and that these connections diminish with pregnancy. The results raise the possibility that the remaining connections from sensory and autonomic subdivisions, particularly the intermediolateral column, of the thoracolumbar spinal cord may be important for increased density of nerve fibers in the cervix as pregnancy nears term.
Gene Genealogies Strongly Distorted by Weakly Interfering Mutations in Constant Environments
Authors: Seger Jon , Smith Wendy A , Perry Jarom J , Hunn Jessalynn , Kaliszewska Zofia A , Sala Luciano La , Pozzi Luciana , Rowntree Victoria J , Adler Frederick R
Published: December 2009

Neutral nucleotide diversity does not scale with population size as expected, and this “paradox of variation” is especially severe for animal mitochondria. Adaptive selective sweeps are often proposed as a major cause, but a plausible alternative is selection against large numbers of weakly deleterious mutations subject to Hill–Robertson interference. The mitochondrial genealogies of several species of whale lice (Amphipoda: Cyamus) are consistently too short relative to neutral-theory expectations, and they are also distorted in shape (branch-length proportions) and topology (relative sister-clade sizes). This pattern is not easily explained by adaptive sweeps or demographic history, but it can be reproduced in models of interference among forward and back mutations at large numbers of sites on a nonrecombining chromosome. A coalescent simulation algorithm was used to study this model over a wide range of parameter values. The genealogical distortions are all maximized when the selection coefficients are of critical intermediate sizes, such that Muller's ratchet begins to turn. In this regime, linked neutral nucleotide diversity becomes nearly insensitive to N. Mutations of this size dominate the dynamics even if there are also large numbers of more strongly and more weakly selected sites in the genome. A genealogical perspective on Hill–Robertson interference leads directly to a generalized background-selection model in which the effective population size is progressively reduced going back in time from the present.
A Comprehensive Linkage Map of the Dog Genome
Authors: Wong Aaron K , Ruhe Alison L , Dumont Beth L , Robertson Kathryn R , Guerrero Giovanna , Shull Sheila M , Ziegle Janet S , Millon Lee V , Broman Karl W , Payseur Bret A , Neff Mark W
Published: December 2009

We have leveraged the reference sequence of a boxer to construct the first complete linkage map for the domestic dog. The new map improves access to the dog's unique biology, from human disease counterparts to fascinating evolutionary adaptations. The map was constructed with ∼3000 microsatellite markers developed from the reference sequence. Familial resources afforded 450 mostly phase-known meioses for map assembly. The genotype data supported a framework map with ∼1500 loci. An additional ∼1500 markers served as map validators, contributing modestly to estimates of recombination rate but supporting the framework content. Data from ∼22,000 SNPs informing on a subset of meioses supported map integrity. The sex-averaged map extended 21 M and revealed marked region- and sex-specific differences in recombination rate. The map will enable empiric coverage estimates and multipoint linkage analysis. Knowledge of the variation in recombination rate will also inform on genomewide patterns of linkage disequilibrium (LD), and thus benefit association, selective sweep, and phylogenetic mapping approaches. The computational and wet-bench strategies can be applied to the reference genome of any nonmodel organism to assemble a de novo linkage map.
Transient Genotype-by-Environment Interactions Following Environmental Shock Provide a Source of Expression Variation for Essential Genes
Authors: Eng Kevin H , Kvitek Daniel J , Keleş Sündüz , Gasch Audrey P
Published: December 2009

Understanding complex genotype-by-environment interactions (GEIs) is crucial for understanding phenotypic variation. An important factor often overlooked in GEI studies is time. We measured the contribution of GEIs to expression variation in four nonlaboratory Saccharomyces cerevisiae strains responding dynamically to a 25°–37° heat shock. GEI was a major force explaining expression variation, affecting 55% of the genes analyzed. Importantly, almost half of these expression patterns showed GEI influence only during the transition between environments, but not in acclimated cells. This class reveals a genotype-by-environment-by-time interaction that affected expression of a large fraction of yeast genes. Strikingly, although transcripts subject to persistent GEI effects were enriched for nonessential genes with upstream TATA elements, those displaying transient GEIs were enriched for essential genes regardless of TATA regulation. Genes subject to persistent GEI influences showed relaxed constraint on acclimated gene expression compared to the average yeast gene, whereas genes restricted to transient GEIs did not. We propose that transient GEI during the transition between environments provides a previously unappreciated source of expression variation, particularly for essential genes.
Signatures of Recent Directional Selection Under Different Models of Population Expansion During Colonization of New Selective Environments
Authors: Kim Yuseob , Gulisija Davorka
Published: December 2009

A major problem in population genetics is understanding how the genomic pattern of polymorphism is shaped by natural selection and the demographic history of populations. Complex population dynamics confounds patterns of variation and poses serious challenges for identifying genomic imprints of selection. We examine patterns of polymorphism using computer simulations and provide analytical predictions for hitchhiking effects under two models of adaptive niche expansion. The population split (PS) model assumes the separation of a founding population followed by directional selection in the new environment. Here, the new population undergoes a bottleneck and later expands in size. This model has been used in previous studies to account for demographic effects when testing for signatures of selection under colonization or domestication. The genotype-dependent colonization and introgression (GDCI) model is proposed in this study and assumes that a small number of migrants carrying adaptive genotype found a new population, which then grows logistically. The GDCI model also allows for constant migration between the parental and the new population. Both models predict reduction in variation and excess of high frequency of derived alleles relative to neutral expectations, with and without hitchhiking. Under comparable conditions, the GDCI model results in greater reduction in expected heterozygosity and more skew of the site frequency spectrum than the PS model. We also find that soft selective sweeps (fixation of multiple copies of a beneficial mutation) occurs less often in the GDCI model than in the PS model. This result demonstrates the importance of correctly modeling the ecological process in inferring adaptive evolution using DNA sequence polymorphism.
The Genetic Signature of Conditional Expression
Authors: Van Dyken J David , Wade Michael J
Published: December 2009

Conditionally expressed genes have the property that every individual in a population carries and transmits the gene, but only a fraction, ϕ, expresses the gene and exposes it to natural selection. We show that a consequence of this pattern of inheritance and expression is a weakening of the strength of natural selection, allowing deleterious mutations to accumulate within and between species and inhibiting the spread of beneficial mutations. We extend previous theory to show that conditional expression in space and time have approximately equivalent effects on relaxing the strength of selection and that the effect holds in a spatially heterogeneous environment even with low migration rates among patches. We support our analytical approximations with computer simulations and delineate the parameter range under which the approximations fail. We model the effects of conditional expression on sequence polymorphism at mutation–selection–drift equilibrium, allowing for neutral sites, and show that sequence variation within and between species is inflated by conditional expression, with the effect being strongest in populations with large effective size. As ϕ decreases, more sites are recruited into neutrality, leading to pseudogenization and increased drift load. Mutation accumulation diminishes the degree of adaptation of conditionally expressed genes to rare environments, and the mutational cost of phenotypic plasticity, which we quantify as the plasticity load, is greater for more rarely expressed genes. Our theory connects gene-level relative polymorphism and divergence with the spatial and temporal frequency of environments inducing gene expression. Our theory suggests that null hypotheses for levels of standing genetic variation and sequence divergence must be corrected to account for the frequency of expression of the genes under study.