bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetative Community Compositional Gradients of Tropical Hardwood Hammocks along the Florida Keys
Authors: Reardon Betty J. , Brooks Wesley R.
Published: September 2008

Tropical hardwood hammocks, among the rarest and most threatened vegetative communities in the United States, occur throughout the 225‐km Florida Keys archipelago as it extends toward the Caribbean from the southeast tip of peninsular Florida. Compounding their critical conservation status, tropical hardwood hammocks and the dynamics that support their peculiar species diversity in the region are poorly understood. The goal of this study was to explore the dynamics of the species compositional gradient of the hammocks along the Florida Keys, and to identify significant ecological units within the gradient. The primary data for this research were assembled from the Institute for Regional Conservation's floristic database of South Florida. We were able to extract presence/absence data for 295 species from comprehensive surveys of 23 study sites. Nonmetric multidimensional scaling was used to deconstruct the compositional trends into a reduced ordination space. Cluster analysis was subsequently used to identify discrete ecological units. Additionally, we used vector fitting to interpret the significant correlated ancillary variables. Our main results were three well‐fitted nonmetric multidimensional scaling axes with three nonoverlapping ecological units. Of the ancillary variables, latitude, longitude, percent composition from biogeographical regions, richness, and area were correlated to the nonmetric multidimensional scaling results. These results increase our understanding of the community structure of the hammocks along the Florida Keys, and can contribute to increasing our ability to adequately protect and restore tropical hardwood hammocks and other similar tropical dry forest communities throughout the Caribbean.
The Rural Physician Associate Program: The Value of Immersion Learning for Third‐Year Medical Students
Authors: Zink Therese , Halaas Gwen W. , Finstad Deborah , Brooks Kathleen D.
Published: September 2008

ABSTRACT: 
Context: Changes in health care and new theories of learning have prompted significant changes in medical education. Some US medical schools employ immersion learning in rural communities to increase the number of physicians who choose to practice in these areas. Founded in 1971, the rural physician associate program (RPAP) is a longitudinal immersion learning experience for students during their third year of medical school. Students are assigned to a primary care preceptor(s) in a rural community ranging in population from 1,000 to 30,000 for 36 weeks. Purpose: To describe students' perceived value of this immersion learning experience. Methods: Data from 3 classes (2004, 2005, 2006) of students (n = 95) were analyzed, including final essays that reflect on their experiences and logs of their patient encounters and procedures. Themes from students' essays related to the hands‐on learning experience are presented. Frequencies of ambulatory encounters and procedures were calculated and compared with those of metropolitan area colleagues where possible. Findings: The continuity experience allows for one‐to‐one mentoring and long‐term relationships. Students see physicians, clinic/hospital staff, and patients as their teachers. The environment is nurturing, but nudges them outside their comfort zone. Students gain increasing competence with their skills and do best if they are independent and seek out learning opportunities. They report more hands‐on experience, more confidence and autonomy than their peers in the metropolitan area. Conclusions: The RPAP experience provides a nurturing, longitudinal, immersion learning experience that facilitates the gradual but steady development of clinical skills alongside a personal and professional mentor.
The Primary Care Physician Workforce in Massachusetts: Implications for the Workforce in Rural, Small Town America
Authors: Stenger Joseph , Cashman Suzanne B. , Savageau Judith A.
Published: September 2008

ABSTRACT: Context:Small towns across the United States struggle to maintain an adequate primary care workforce.Purpose:To examine factors contributing to physician satisfaction and retention in largely rural areas in Massachusetts, a state with rural pockets and small towns.Methods:A survey mailed in 2004‐2005 to primary care physicians, practicing in areas designated by the state as rural, queried respondents about personal and practice characteristics as well as workforce concerns. Predictors of satisfaction and likelihood of remaining in current or rural practice somewhere were assessed.Findings:Of 227 eligible physicians, 160 returned their surveys (response rate, 70.5%). Approximately one third (34.0%) reported they had grown up in communities of 100,000 or larger. Factors associated with higher overall practice satisfaction included not feeling overworked (P = .043) or professionally isolated (P = .004), and being involved in their practice (P = .045) and home communities (P = .036) as well as ease of seeking additional physicians for practice and obtaining CME credits (P = .014 and P = .017, respectively). Female physicians were more likely to report an intention to remain in rural practice somewhere for the next decade (P = .034). In rating their satisfaction with various aspects of the rural practice environment, physicians reported greatest satisfaction with their practice overall (67%) and their call group size (66%). They were least satisfied with their current (30%) and likely future income (40%). In multivariate analyses, larger practice community size was positively related to the dependent variable of overall satisfaction and negatively related to likelihood of staying in current practice or in rural practice somewhere.Conclusions:Our findings reaffirm the importance of rural medical education opportunities in physician recruitment, retention, and practice satisfaction. They also indicate that in a small New England state, a major source of physicians for rural and small town communities is physicians who have been raised in urban/suburban communities and who were trained outside of the region but who were prepared to live and to practice in rural and small town communities.
The Physician Pipeline to Rural and Underserved Areas in Pennsylvania
Authors: Schwartz Myron R.
Published: September 2008

ABSTRACT: 
Context: An implicit objective of a state's investments in medical education is to promote in‐state practice of state educated physicians. Purpose: To present a tool for evaluating this objective by analyzing the “pipeline” from medical education to patient care, primary care, rural areas, and underserved areas in Pennsylvania. Methods: AMA Masterfile data (2004) including all physicians with a Pennsylvania address or who received medical education in Pennsylvania were analyzed. These data were combined with local physician supply data. Results: About 36% of Pennsylvania medical school graduates provide patient care in the Commonwealth, 16% primary care, 7% rural care, 4% rural primary care, and 0.5% primary care in a rural underserved area. Fifty‐four percent of physicians who received both undergraduate and graduate medical education in‐state are retained. Conclusions: These retention rates have developed within the context of a middle‐of‐the‐road educational pipeline policy. If Pennsylvania policy makers consider that further pipeline development is advisable, there is room to amend current policy to that end. Conditions are favorable for other states to consider similar policy amendments.
Access to Cancer Services for Rural Colorectal Cancer Patients
Authors: Baldwin Laura‐Mae , Cai Yong , Larson Eric H. , Dobie Sharon A. , Wright George E. , Goodman David C. , Matthews Barbara , Hart L. Gary
Published: September 2008

ABSTRACT: 
Context: Cancer care requires specialty surgical and medical resources that are less likely to be found in rural areas. Purpose: To examine the travel patterns and distances of rural and urban colorectal cancer (CRC) patients to 3 types of specialty cancer care services—surgery, medical oncology consultation, and radiation oncology consultation. Methods: Descriptive cross‐sectional study using linked Surveillance, Epidemiology, and End Results (SEER) cancer registry and Medicare claims data for 27,143 individuals ages 66 and older diagnosed with stages I through III CRC between 1992 and 1996. Findings: Over 90% of rural CRC patients lived within 30 miles of a surgical hospital offering CRC surgery, but less than 50% of CRC patients living in small and isolated small rural areas had a medical or radiation oncologist within 30 miles. Rural CRC patients who traveled outside their geographic areas for their cancer care often went great distances. The median distance traveled by rural cancer patients who traveled to urban cancer care providers was 47.8 miles or more. A substantial proportion (between 19.4% and 26.0%) of all rural patients bypassed their closest medical and radiation oncology services by at least 30 miles. Conclusions: Rural CRC patients often travel long distances for their CRC care, with potential associated burdens of time, cost, and discomfort. Better understanding of whether this travel investment is paid off in improved quality of care would help rural cancer patients, most of whom are elderly, make informed decisions about how to use their resources during their cancer treatment.
Impact of Critical Access Hospital Conversion on Beneficiary Liability
Authors: Gilman Boyd H.
Published: September 2008

ABSTRACT: 
Context: While the Medicare Critical Access Hospital (CAH) program has improved the financial viability of small rural hospitals and enhanced access to care in rural communities, the program puts beneficiaries at risk for paying a larger share of the cost of services covered under the Medicare part B benefit. Purpose: This paper examines the impact of hospital conversion to CAH status on beneficiary out‐of‐pocket coinsurance payments for hospital outpatient services. Methods: The study is based on a retrospective observational design using administrative data from Medicare hospital cost reports and fee‐for‐service beneficiary claims from 1999 to 2003. The study compares changes in beneficiary co‐payments before versus after CAH conversion with payment trends among small rural non‐converting hospitals over the same period. Findings: Conversion to CAH status is associated with an increase in beneficiary coinsurance payments per outpatient visit of $17.19, equivalent to 34% of the sample average. However, CAH designation had no significant effect on the share of outpatient costs paid by the beneficiary. Most of the increase in beneficiary liability associated with conversion is attributable to the provision of more services per outpatient visit. Conclusions: While this and other studies show that conversion to CAH status results in more intensive outpatient care, CAH conversion does not appear to inadvertently create financial barriers to accessing ambulatory services in remote rural communities by forcing beneficiaries to pay a higher share of their Medicare part B costs.
Spontaneous reversion of complete A‐V block to sinus rhythm in the dog
Authors: DEAR M. G.
Published: September 2008

A case of complete atrioventricular block in a dog is reported. Emphasis is placed upon the spontaneous reversion of the dysrhythmia to sinus rhythm. The clinical veterinary literature on complete block is reviewed with particular reference to the incidence of the condition, the aetiology of complete block, the aetiology of Stokes—Adams attacks, the clinical features of the latter and the nature of the block, whether acquired or congenital. Comparative features with the human analogue of the dysrhythmia are discussed.

Résumé.On rapporte le cas d'un bloc atrio‐ventriculaire complet chez un chien. On souligne la reversion spontanée de la dysrythmie en rythme sinusal. La littérature vétérinaire clinique sur le bloc complet du ceur est passée en révue et on souligne particulièrement la fréquence relative de cet état, l'étiologie du bloc complet et celle des accès de Stokes—Adams. Le tableau clinique de ce dernier syndrome et la nature du bloc atrioventriculaire acquis ou congénital sont décrits. On discute les analogies entre Ie cas de dysrythmie présenté ici et l'affection analogue dans l'espèce humaine.

Zusammenfassung.Es wird über einen Fall von vollständigem atrioventrikularem Block bei einem Hund berichtet. Hervorgehoben wird die spontane Rückkehr von der Dysrhythmie zum Sinusrhythmus. Die tierärztliche klinische Literatur über den vollständigen Block wird besonders hinsichtlich der Häufigkeit des Zustands, der Ätiologie des vollständigen Blocks, der Ätiologie der Stokes—Adams‐Anfälle, ihrer klinischen Merkmale und des Charakters des Blocks, ob erworben oder kongenital, betrachtet. Vergleichbare Merkmale der analogen Dysrhythmie beim Menschen werden besprochen.
An unusual combination of congenital cardiac anomalies in a cat
Authors: DEAR M. G.
Published: September 2008

A case of a congenital cardiac anomaly in a cat is described. The anomaly includes a patent ductus arteriosus, an interatrial septal defect, an interventricular septal defect and tricuspid insufficiency. An umbilical hernia was present also. Emphasis is placed on the relationship of the auscultatory, radiographic and electrocardiographic features and the pathological findings.

Résumé. On décrit un cas d'anomalie cardiaque congénitale chez un chat; cette anomalie comprenait la présence d'un carnal artériel, d'une communication inter‐auriculaire septale, d'une communication inter‐ventriculaire septale et d'une insuffisance tricuspidienne. L'animal était atteint aussi d'une hernie ombilicale. On souligne les rapports entre les données de l'auscultation, de la radiographie, de l'électro‐cardiographie et les lésions anatomopathologiques.

Zusammenfassung. Ein Fall einer kongenitalen Herzanomalie bei einer Katze wird beschrieben. Zu der Anomalie gehören ein Ductus arteriosus apertus, ein interatrialer Septumdefekt, ein interventrikularer Septumdefekt und Tricuspidalinsuffizienz. Ausserdem lag ein Nabelbruch vor. Besonderes Gewicht wird auf die Beziehung der Auskultation, Radiographie und Elektrokardiographie zum pathologischen Befund gelegt.
Eurasian blackbird predated by wildRhinopithecus roxellanain the Qinling Mountains, China
Authors: ZHAO Dapeng , WANG Xiaowei , WATANABE Kunio , LI Baoguo
Published: September 2008

Although there are some reports that have described primates eating animals, it is unknown whether predation on vertebrates exists in herbivorous leaf‐eating primates. We have witnessed firsthand wild Sichuan snub‐nosed monkeys (Rhinopithecus roxellana) preying on and consuming Eurasian blackbirds (Turdus meruld) in the Qinling Mountains of China. This event suggests thatR. roxellana, which has previously been described as a herbivorous leaf‐eating primate, may be partially carnivorous and the correct classification of this species would be omnivorous. Furthermore, food‐share behavior among higher‐ranked members occurs in a one‐male unit when vertebrate prey is hunted by this species.
A rare autosomal recessive condition, congenital erythropoietic porphyria, found in the canefield rat Rattus sordidus Gould 1858
Authors: RIVERA Dario F. , LEUNG Luke K.‐P.
Published: September 2008

Congenital erythropoietic porphyria (CEP) is a rare autosomal recessive condition that has been reported in humans and in some animals, in which uroporphyrin 1 is deposited in the bones, teeth and urine, resulting in pink coloration and fluorescence of the tissues and urine under long‐wave ultraviolet (UV) light. We observed red teeth in nine of 450 canefield rats (Rattus sordidus) captured in a small, isolated patch of sugarcane in Tully, north Queensland, Australia. The skeletons of these animals were excised and were found to be bright red under normal day light. Under UV light, the skeleton had a bright red fluorescence. It is plausible that the canefield rat population in this isolated patch of sugarcane is small and inbreeding might have occurred, resulting in incidences of the autosomal recessive genes that cause CEP. The canefield rat can be used as an animal model for research into porphyria.
Effect of frugivorous birds on the establishment of a naturally regenerating population of Chinese yew in ex situ conservation
Authors: LU Changhu , ZHU Qiongqiong , DENG Qingshan
Published: September 2008

The Chinese yew (Taxus chinensis) is catalogued as an endangered species in China because of the small size and senescent status of most populations. Its lack of natural regeneration is the most important reason for its endangered status. We investigated the regeneration of an ex‐situ conservation population, which was introduced into the Nanjing Botanical Garden Memorial Sun Yat‐Sen in the 1950s, and evaluated the role of frugivorous birds on the establishment of this regenerating population. Two hundred and thirteen individual yew seedlings and saplings were found on the hillside in 2006, and the nearest seedling was found more than 10 m away from mother trees. The spatial pattern of all seedlings and saplings occurred as a clumped distribution, which is typical for vertebrate‐dispersed plants. Six bird species were seen ingesting whole “fruits” at yew trees in the present study and 745 visits by avian frugivores were recorded. Red‐billed blue magpie (Urocissa erythrorhyncha), Chinese bulbul (Pycnonotus sinensis) and azure‐winged magpie (Cyanopica cyana) were the most frequent visitors over the two years of the study. Comparing the flights of departure and perching habitats of the three main bird species, we inferred that U. erythrorhyncha would be the most important disperser. This regeneration population has had good development over the past 20 or more years; frugivorous birds have removed seeds to the hillside every year until now, and seed germination and seedling growth continue to develop well under natural conditions. We suggest that the conservation system of the Chinese yew should be composed of yews, avian dispersers and habitats for seed germination and seedling growth.
Global potential distribution of an invasive species, the yellow crazy ant (Anoplolepis gracilipes) under climate change
Authors: CHEN Youhua
Published: September 2008

Changes to the Earth's climate may affect the distribution of countless species. Understanding the potential distribution of known invasive species under an altered climate is vital to predicting impacts and developing management policy. The present study employs ecological niche modeling to construct the global potential distribution range of the yellow crazy ant (Anoplolepis gracilipes) using past, current and future climate scenarios. Three modeling algorithms, GARP, BioClim and Environmental Distance, were used in a comparative analysis. Output from the models suggest firstly that this insect originated from south Asia, expanded into Europe and then into Afrotropical regions, after which it formed its current distribution. Second, the invasive risk of A. gracilipes under future climatic change scenarios will become greater because of an extension of suitable environmental conditions in higher latitudes. Third, when compared to the GARP model, BioClim and Environmental Distance models were better at modeling a species' ancestral distribution. These findings are discussed in light of the predictive accuracy of these models.
Karyotypes of three shrew species (Soriculus nigrescens, Episoriculus caudatus and Episoriculus sacratus) from Nepal
Authors: MOTOKAWA Masaharu , HARADA Masashi , MEKADA Kazuyuki , SHRESTHA Krishna C.
Published: September 2008

The karyotypes of three shrew species (Mammalia, Soricomorpha, Soricidae) from Nepal were examined for the first time. Based on the karyotypes and overall differences in skull size, the current Episoriculus caudatus appeared to include two distinct species: the larger E. caudatus and the smaller Episoriculus sacratus. Episoriculus sacratus has three subspecies, E. s. soluensis in Nepal and Sikkim, E. s. umbrinus in Assam, Myanmar and the Yunnan Province of China, and E. s. sacratus in the Sichuan Province of China. Soriculus nigrescens had a diploid chromosome number (2n) and fundamental number (FN), including two X chromosomes, of 64 and 92, respectively, consisting of 11 metacentric or submetacentric, two subtelocentric and 18 acrocentric pairs of autosomes, a metacentric X and an acrocentric Y chromosome. Episoriculus sacratus soluensis had 2n = 74 and FN = 126, consisting of 12 metacentric or submetacentric, 13 subtelocentric and 11 acrocentric pairs of autosomes, a submetacentric X and an acrocentric Y chromosome. Episoriculus caudatus had 2n = 60 and FN = 118, consisting of 19 metacentric or submetacentric, nine subtelocentric and one acrocentric pair of autosomes, a subtelocentric X and an acrocentric Y chromosome. The karyotypes of these three species are characterized by their large 2n and FN values compared with other Soricidae.
Comparative morphometrics of two populations of giant river catfish (Mystus seenghala) from the Indus river system
Authors: SAINI Archana , DUA Anish , MOHINDRA Vindhya
Published: September 2008

Giant river catfish (Mystus seenghala) from the Beas river were compared with a population in the Sutlej river of the Indus river system using 28 morphometric characters. Discriminant analyses and a univariate anova were used to explore these data. Allometric transformation of each measurement was done to eliminate correlations with size. The stepwise discriminant analysis retained nine variables that significantly discriminated the Beas samples from the Sutlej samples. Using these variables, 91.2% (original) and 89.0% (cross validated) of fish were classified into their correct samples. Misclassification was higher for the Sutlej samples (12.5%) than for the Beas samples (6.3%). The results of the discriminant analyses showed that variability in the Beas samples was more homogeneous and provided a more characteristic picture of the group than the Sutlej samples. The univariate ANOVA revealed significant differences between the means of the two populations for 12 of the 28 transformed morphometric measurements.
Applications of graph theory to landscape genetics
Authors: Garroway Colin J. , Bowman Jeff , Carr Denis , Wilson Paul J.
Published: September 2008

We investigated the relationships among landscape quality, gene flow, and population genetic structure of fishers (Martes pennanti) in ON, Canada. We used graph theory as an analytical framework considering each landscape as a network node. The 34 nodes were connected by 93 edges. Network structure was characterized by a higher level of clustering than expected by chance, a short mean path length connecting all pairs of nodes, and a resiliency to the loss of highly connected nodes. This suggests that alleles can be efficiently spread through the system and that extirpations and conservative harvest are not likely to affect their spread. Two measures of node centrality were negatively related to both the proportion of immigrants in a node and node snow depth. This suggests that central nodes are producers of emigrants, contain high‐quality habitat (i.e., deep snow can make locomotion energetically costly) and that fishers were migrating from high to low quality habitat. A method of community detection on networks delineated five genetic clusters of nodes suggesting cryptic population structure. Our analyses showed that network models can provide system‐level insight into the process of gene flow with implications for understanding how landscape alterations might affect population fitness and evolutionary potential.
Segmental vitiligo as the possible expression of cutaneous somatic mosaicism: implications for common non‐segmental vitiligo
Authors: Taïeb Alain , Morice‐Picard Fanny , Jouary Thomas , Ezzedine Khaled , Cario‐André Muriel , Gauthier Yvon
Published: September 2008

Clinical findings in vitiligo challenge the widely accepted organ specific autoimmune pathomechanisms. We draw the attention to the fact that the distribution of segmental vitiligo (SV) fits in at least a subset of patients a pattern usually associated with cutaneous mosaicism. The association of SV to non‐segmental vitiligo (NSV) now confirmed by several observations indicates a continuum between the two subsets with shared predisposing genetic factors, including genes operating specifically in the skin. Some pedigrees associating SV and NSV further suggest a mechanism of loss of heterozygosity for a dominant gene controlling part of the cutaneous phenotype. The mosaic hypothesis applies only to SV and to the rare SV‐NSV association, but suggests that predisposing genetic factors in common NSV should also be searched directly in the skin. SV would be a good candidate disease to explore as a proof of principle of a new gene discovery strategy useful for multigenic disorders with organ specificity, applicable in priority to chronic inflammatory skin disorders.
Gouverner l'innovation, entre sciences dures et arts plastiques: le consortium interuniversitaire Hexagram (Montréal, Canada)*
Authors: FOURMENTRAUX JEAN‐PAUL
Published: September 2008

In the academic stream of technological arts, the national systems of innovation are involved in a reconfiguration of research and development organizations, which are aimed at marketing hybrid products that are now concurrently oriented towards artistic presentation, technology transfer and an application in both the commercial and industrial sense. This article provides an initial analysis of the motives and organizational pressures involved in these attempts to integrate and articulate academic research, artistic creation and industrial production in a perspective of competitiveness in innovation. It draws on the results of a survey conducted with artist‐researchers who created a Canadian organizational prototype of these partnerships: the Hexagram inter‐university consortium (Montréal, Canada).

Les ← systèmes d'innovation nationaux → engagent dans la filière universitaire des arts technologiques une reconfiguration des organisations de recherche et de création. Ces dernières visent la mise sur le marché de produits hybrides orientés désormais concurremment vers une exposition artistique, une valorisation scientifique et une application au sens commercial et industriel du terme. L'article propose une première analyse des ressorts et tensions organisationnelles de ces tentatives d'intégration et d'articulation de la recherche universitaire, de la création artistique et de la production industrielle dans une perspective de concurrence à l'innovation. Il mobilise les résultats d'une enquête menée auprès de chercheurs‐créateurs d'un prototype canadien d'organisation de ces rapprochements: le consortium interuniversitaire Hexagram (Montréal, Canada).
Mobilization of Personal Social Networks and Institutional Resources of Private Entrepreneurs in China*
Authors: FONG ERIC , CHEN WENHONG
Published: September 2008

Les auteurs examinent les liens micro et macroscopiques dans l'étude de l'économie en transition, en analysant la façon dont les entrepreneurs mobilisent leurs réseaux sociaux personnels intégrés à diverses institutions, afin de protéger leurs ressources d'affaires. Les résultats démontrent que les membres du réseau travaillant dans les organismes du gouvernement ou du parti jouent, en gros, un rôle essentiel dans l'obtention des ressources importantes comme les contacts gouvernementaux et l'information sur le marché et le financement. Ils démontrent aussi que les entrepreneurs utilisent différents membres de leurs réseaux pour différents types de ressources. Les auteurs discutent les différentes conséquences que cela entraine pour l'étude des réseaux et de l'économie en transition.

This paper addresses the micro and macro link in studying transitional economy by examining how entrepreneurs mobilize their personal social networks embedded in various institutions to secure business resources. The results show that, by and large, network members working in government/party agencies play an essential role in obtaining important resources, such as those for government contact and market information/funding. The results also show that entrepreneurs utilize different members of their networks for different types of resources. Implications to the study of networks and transitional economy are discussed.
Hospital Volunteers and Carework*
Authors: MELLOW MURIEL
Published: September 2008

L'auteure analyse les soins fournis par des bénévoles d'hôpitaux en utilisant des données d'entrevues, des descriptions de täches et des statistiques concernant les bénévoles de quatre hôpitaux d'Alberta, Canada. Les employés des hôpitaux s'attendent à ce que les bénévoles fournissent des soins instrumentaux et affectifs, mais ils restreignent également leur tàche en imposant des limites aux heures de travail réalisé par les bénévoles ainsi qu'à la somme d'information qu'ils reçoivent sur les patients. Les bénévoles surmontent ces contraintes en entretenant des conversations informelles destinées à augmenter leurs connaissances, tout en étant flexibles par rapport aux heures accordées aux patients, afin de pouvoir s'occuper de leurs besoins émotionnels. L'auteure considère également la répartition des sexes chez les bénévoles et l'influence qu'elle exerce sur leurs attentes.

Carework done by hospital volunteers is examined using interview data, task descriptions and volunteer statistics from four hospitals in Alberta, Canada. Hospitals expect volunteers to provide instrumental and affective care but also constrain this work by limiting volunteers' work time and the amount of information they are given about patients. Volunteers overcome these constraints by initiating informal conversation to broaden their knowledge and capitalizing on flexibility in how they spend their time to attend to patients' emotional needs. I also consider how the volunteer workforce is gendered and how this influences expectations of volunteers.
Stark–Heegner points and the Shimura correspondence
Authors: Darmon Henri , Tornaría Gonzalo
Published: September 2008

Let $g = \sum c(D)q^D$ and $f=\sum a_n q^n$ be modular forms of half-integral weight k+1/2 and integral weight 2k respectively that are associated to each other under the Shimura–Kohnen correspondence. For suitable fundamental discriminants D, a theorem of Waldspurger relates the coefficient c(D) to the central critical value L(f,D,k) of the Hecke L-series of f twisted by the quadratic Dirichlet character of conductor D. This paper establishes a similar kind of relationship for central critical derivatives in the special case k=1, where f is of weight 2. The role of c(D) in our main theorem is played by the first derivative in the weight direction of the Dth Fourier coefficient of a p-adic family of half-integral weight modular forms. This family arises naturally, and is related under the Shimura correspondence to the Hida family interpolating f in weight 2. The proof of our main theorem rests on a variant of the Gross–Kohnen–Zagier formula for Stark–Heegner points attached to real quadratic fields, which may be of some independent interest. We also formulate a more general conjectural formula of Gross–Kohnen–Zagier type for Stark–Heegner points, and present numerical evidence for it in settings that seem inaccessible to our methods of proof based on p-adic deformations of modular forms.
On the classification of rank-two representations of quasiprojective fundamental groups
Authors: Corlette Kevin , Simpson Carlos
Published: September 2008

Suppose that X is a smooth quasiprojective variety over ℂ and ρ:π1(X,x)→SL(2,ℂ) is a Zariski-dense representation with quasiunipotent monodromy at infinity. Then ρ factors through a map X→Y with Y either a Deligne–Mumford (DM) curve or a Shimura modular stack.
On the lifting of hermitian modular forms
Authors: Ikeda Tamotsu
Published: September 2008

Let K be an imaginary quadratic field with discriminant −D. We denote by 𝒪 the ring of integers of K. Let χ be the primitive Dirichlet character corresponding to K/ℚ. Let $\Gamma ^{(m)}_K=\mathrm {U} (m,m)({\mathbb Q})\cap \mathrm {GL}_{2m}({\cal O})$ be the hermitian modular group of degree m. We construct a lifting from S2k(SL2(ℤ)) to S2k+2n(ΓK(2n+1),det −k−n) and a lifting from S2k+1(Γ0(D),χ) to S2k+2n(ΓK(2n),det −k−n). We give an explicit Fourier coefficient formula of the lifting. This is a generalization of the Maass lift considered by Kojima, Krieg and Sugano. We also discuss its extension to the adele group of U(m,m).
Counting Morse functions on the 2-sphere
Authors: Nicolaescu Liviu I.
Published: September 2008

We count how many ‘different’ Morse functions exist on the 2-sphere. There are several ways of declaring that two Morse functions f and g are ‘indistinguishable’ but we concentrate only on two natural equivalence relations: homological (when the regular sublevel sets f and g have identical Betti numbers) and geometric (when f is obtained from g via global, orientation-preserving changes of coordinates on S2 and ℝ). The count of homological classes is reduced to a count of lattice paths confined to the first quadrant. The count of geometric classes is reduced to a count of certain labeled trees, which is encoded by certain elliptic integrals.
Stable/Unstable Stratification in Thermosolutal Convection in a Square Cavity
Authors: Maiti D. K. , Gupta A. S. , Bhattacharyya S.
Published: September 2008

A numerical study is made of double-diffusive convection in a square cavity with a sliding top lid in the presence of combined vertical temperature and concentration gradients. The bottom lid and other two walls are kept fixed. The side walls are adiabatic and impermeable to solute while the top and bottom lids are kept at constant but distinct temperature and concentration. The governing unsteady Navier–Stokes equations combined with the heat and mass transport equations are solved numerically through a finite volume method on a staggered grid system using QUICK scheme for convective terms. The resulting equations are then solved by an implicit, time-marching, pressure correction-based algorithm. The flow configuration is classified into four cases depending on positive/negative values of thermal Grashof number and solutal Grashof number. A detailed comparison of the four flow configurations is made in this paper. In conclusion, these four flow configurations can be brought to either stably or unstably stratified field. Furthermore, the possibility of salt-fingering and double-diffusive instability in the absence of the top lid motion is explored and the effect of the lid motion is clearly exhibited. The dependence of the average rates of heat and mass transfer from the top and bottom lids on the flow parameters is also investigated in the presence of top lid motion.
Heat Exchanger Analysis Modified to Account for a Heat Source
Authors: Narayanan Vinod , Kanury Murty , Jenks Jeromy
Published: September 2008

A modified heat exchanger analysis is developed here that accounts for a heat source, which is assumed to be volumetrically uniform in the hot fluid. The motivation for this work arises from the analysis of an ammonia-water absorber heat exchanger where a heat-of-absorption source term arises in the solution side. Utility of the analysis in deducing the overall heat transfer coefficient from experimental measurements is demonstrated.
Liquid Single-Phase Flow in an Array of Micro-Pin-Fins—Part I: Heat Transfer Characteristics
Authors: Qu Weilin , Siu-Ho Abel
Published: September 2008

This is Paper I of a two-part study concerning thermal and hydrodynamic characteristics of liquid single-phase flow in an array of micro-pin-fins. This paper reports the heat transfer results of the study. An array of 1950 staggered square micro-pin-fins with 200×200 μm2 cross-section by 670 μm height were fabricated into a copper test section. De-ionized water was used as the cooling liquid. Two coolant inlet temperatures of 30°C and 60°C and six maximum mass velocities for each inlet temperature ranging from 183 to 420 kg/m2 s were tested. The corresponding inlet Reynolds number ranged from 45.9 to 179.6. General characteristics of average and local heat transfer were described. Six previous conventional long and intermediate pin-fin correlations and two micro-pin-fin correlations were examined and were found to overpredict the average Nusselt number data. Two new heat transfer correlations were proposed for the average heat transfer based on the present data, in which the average Nusselt number is correlated with the average Reynolds number by power law. Values of the exponent m of the Reynolds number for the two new correlations are fairly close to those for the two previous micro-pin-fin correlations but substantially higher than those for the previous conventional pin-fin correlations, indicating a stronger dependence of the Nusselt number on the Reynolds number in micro-pin-fin arrays. The correlations developed for the average Nusselt number can adequately predict the local Nusselt number data.
Time-Resolved Micro-Raman Thermometry for Microsystems in Motion
Authors: Serrano Justin R. , Kearney Sean P.
Published: September 2008

Micro-Raman thermometry has been demonstrated to be a feasible technique for obtaining surface temperatures with micron-scale spatial resolution for microelectronic and microelectromechanical systems (MEMSs). However, the intensity of the Raman signal emerging from the probed device is very low and imposes a requirement of prolonged data collection times in order to obtain reliable temperature information. This characteristic currently limits Raman thermometry to steady-state conditions and thereby prevents temperature measurements of transient and fast time-scale events. In this paper, we discuss the extension of the micro-Raman thermometry diagnostic technique to obtain transient temperature measurements on microelectromechanical devices with 100 μs temporal resolution. Through the use of a phase-locked technique we are able to obtain temperature measurements on electrically powered MEMS actuators powered with a periodic signal. Furthermore, we demonstrate a way of obtaining reliable temperature measurements on micron-scale devices that undergo mechanical movement during the device operation.
A Fixed-Angle Dynamic Heat Spreading Model for (An)Isotropic Rear-Cooled Substrates
Authors: Vermeersch Bjorn , De Mey Gilbert
Published: September 2008

During a period of almost 40 years already, various fixed-angle heat spreading models have been developed in the literature. These models are commonly used by thermal engineers as approximations for the thermal steady-state resistance of a heat source on a rear-cooled substrate. In this paper, an extension of these models to dynamic (time-dependent) phenomena is proposed. The heat dissipated by a square source (side a) is assumed to spread out into the substrate (thickness b) under an angle ϕ. An analytical solution for the complex thermal impedance Zth(jω) in phasor notation is derived. The obtained expression, in which ϕ is used as a fitting parameter, is compared with accurate analytical results. A very good agreement is observed (average relative error less than 6%) for a wide range of the normalized thickness λ=b/a. A compact expression for the optimal heat spreading angle as a function of λ is given. Also the temperature response to a heat power step is investigated, and a simple formula for the thermal rise time is provided. Finally, the model can be easily extended to anisotropic media, which often appear in electronic packaging applications. Overall the proposed model allows a thermal designer to make quick yet accurate estimations about the dynamic behavior of the device.
Single- and Dual-Phase-Lagging Heat Conduction Models in Moving Media
Authors: Cheng Lin , Xu Mingtian , Wang Liqiu
Published: September 2008

Motivated by the recent work of Christov and Jordan, (“Heat Conduction Paradox Involving Second-Sound Propagation in Moving Media,” 2005, Phys. Rev. Lett., 94, p. 154301), we examine the original single- and dual-phase-lagging heat conduction models without Taylor series approximation and their variants in moving media using the Galilean principle of relativity. It is found that the original single- and dual-phase-lagging heat conduction models are Galilean invariant and lead to a single governing equation even for the multidimensional media. However their variants violate the Galilean principle of relativity in the moving media. Although this paradox can be eliminated by replacing the partial time derivatives with the material derivatives, the resulting governing equations cannot be reduced to a single transport equation in the multidimensional media. Therefore we believe that the original single- and dual-phase-lagging heat conduction models are more advantageous in modeling the microscale heat conduction problems.
Estimating the Wall Heat Flux of Unsteady Conjugated Forced Convection Between Two Corotating Disks Using an Inverse Solution Scheme
Authors: Lin David T. W. , Li Hung Yi , Yan Wei Mon
Published: September 2008

An inverse solution scheme based on the conjugate gradient method with the minimization of the object function is presented for estimating the unknown wall heat flux of conjugated forced convection flows between two corotating disks from temperature measurements acquired within the flow field. The validity of the proposed approach is demonstrated via the estimation of three time- and space-dependent heat flux profiles. A good agreement is observed between the estimated results and the exact solution in every case. In general, the accuracy of the estimated results is found to improve as the temperature sensors are moved closer to the unknown boundary surface and the error in the measured temperature data is reduced.
Antibody Responses of Cervids (Cervus elaphus) following ExperimentalMycobacterium bovisInfection and the Implications for Immunodiagnosis
Authors: Harrington Noel P. , Surujballi Om P. , Prescott John F. , Duncan J. Robert , Waters W. Ray , Lyashchenko Konstantin , Greenwald Rena
Published: September 2008

Captive and free-ranging wildlife animals are implicated in the maintenance and transmission of bovine tuberculosis and therefore pose a significant obstacle to eradication of the disease from domestic livestock. The current antemortem diagnostic method, the intradermal tuberculin skin test, is impractical for routine use with many wild animals. Antibody-based assays are particularly attractive because the animals are handled only once and immediate processing of the sample is not required. This report characterizes the antibody responses of red deer-elk hybrids (Cervus elaphus) againstMycobacterium bovisand subsequently evaluates the diagnostic performance of select antigens in a rapid-test format. Sequential serum samples were collected from 10 animals experimentally infected withM. bovisand 5 noninfected animals over a 7-month period postinfection (p.i.). Samples were evaluated by enzyme-linked immunosorbent assays, immunoblot analyses, and multiantigen print immunoassays for seroreactivity to mycobacterial antigens. Although all infected animals produced antibodies toM. bovisprotein antigens, there was significant animal-to-animal variation in the kinetics and magnitudes of responses and the antigens recognized. The most frequently recognized antigens included MPB83, ESAT-6, CFP10, and MPB70. Responses to some antigens, such as MPB83, were consistently detected as early as 4 weeks after inoculation, whereas other antigens were detected only much later (>140 days p.i.). Antibody responses were boosted by injection of tuberculin for intradermal tuberculin skin testing. Comparison of single-antigen (fluorescence polarization assay) with multiantigen (CervidTB STAT-PAK) rapid tests demonstrated that a highly sensitive and specific serodiagnostic test for tuberculosis in cervids will require multiple and carefully selected seroreactive antigens covering a broad spectrum of antibody specificities.
Kaposi's Sarcoma-Associated Herpesvirus Disrupts Adherens Junctions and Increases Endothelial Permeability by Inducing Degradation of VE-Cadherin
Authors: Qian Li-Wu , Greene Whitney , Ye Fengchun , Gao Shou-Jiang
Published: September 2008

Kaposi's sarcoma (KS) is a vascular tumor of proliferative endothelial cells caused by KS-associated herpesvirus (KSHV) infection. Aberrant vascular permeability is a hallmark of KS manifested as multifocal edematous skin and visceral lesions with dysregulated angiogenesis and vast inflammatory infiltrations. In this study, we showed that KSHV infection increased the permeability of confluent endothelial monolayers to serum albumin, blood-derived cells, KSHV-infected cells, and KSHV virions. KSHV-induced permeability was associated with the disruption of adherens junctions and the degradation of vascular endothelial cadherin (VE-cadherin) protein. Both the inactivation of KSHV virions by UV irradiation and the blockage of de novo protein synthesis with cycloheximide failed to reverse the KSHV-induced disruption of adherens junctions. However, soluble heparin that blocked KSHV entry into cells completely inhibited KSHV-induced permeability. Furthermore, the KSHV-induced degradation of VE-cadherin was dose dependent on the internalized virus particles. Together, these results indicate that KSHV infection induces vascular permeability by inducing VE-cadherin degradation during virus entry into cells. KSHV-induced aberrant vascular permeability could facilitate virus spread, promote inflammation and angiogenesis, and contribute to the pathogenesis of KSHV-induced malignancies.
Murine Coronaviruses Encoding nsp2 at Different Genomic Loci Have Altered Replication, Protein Expression, and Localization
Authors: Gadlage Mark J. , Graham Rachel L. , Denison Mark R.
Published: September 2008

Partial or complete deletion of several coronavirus nonstructural proteins (nsps), including open reading frame 1a (ORF1a)-encoded nsp2, results in viable mutant proteins with specific replication defects. It is not known whether expression of nsps from alternate locations in the genome can complement replication defects. In this report, we show that the murine hepatitis virus nsp2 sequence was tolerated in ORF1b with an in-frame insertion between nsp13 and nsp14 and in place of ORF4. Alternate encoding or duplication of the nsp2 gene sequence resulted in differences in nsp2 expression, processing, and localization, was neutral or detrimental to replication, and did not complement an ORF1a Δnsp2 replication defect. The results suggest that wild-type genomic organization and expression of nsps are required for optimal replication.
Estimating In Vivo Death Rates of Targets due to CD8 T-Cell-Mediated Killing
Authors: Ganusov Vitaly V. , De Boer Rob J.
Published: September 2008

Despite recent advances in immunology, several key parameters determining virus dynamics in infected hosts remain largely unknown. For example, the rate at which specific effector and memory CD8 T cells clear virus-infected cells in vivo is hardly known for any viral infection. We propose a framework to quantify T-cell-mediated killing of infected or peptide-pulsed target cells using the widely used in vivo cytotoxicity assay. We have reanalyzed recently published data on killing of peptide-pulsed splenocytes by cytotoxic T lymphocytes and memory CD8 T cells specific to NP396 and GP276 epitopes of lymphocytic choriomeningitis virus (LCMV) in the mouse spleen. Because there are so many effector CD8 T cells in spleens of mice at the peak of the immune response, NP396- and GP276-pulsed targets are estimated to have very short half-lives of 2 and 14 min, respectively. After the effector numbers have diminished, i.e., in LCMV-immune mice, the half-lives become 48 min and 2.8 h for NP396- and GP276-expressing targets, respectively. Analysis of several alternative models demonstrates that the estimates of half-life times of peptide-pulsed targets are not affected when changes are made in the model assumptions. Our report provides a unifying framework to compare killing efficacies of CD8 T-cell responses specific to different viral and bacterial infections in vivo, which may be used to compare efficacies of various cytotoxic-T-lymphocyte-based vaccines.