cssi/SciSciGPT-SciSciNet huggingface dataset:
Epidemic typhus rickettsiae isolated from flying squirrels.

EPIDEMIC typhus is a severe rickettsial infection that classically has involved only man and his body louse. Although the aetiological agent, Rickettsia prowazekii, has been isolated from ticks of domestic animals and from blood of livestock in Ethiopia and Egypt1,2, infection of these unusual hosts and vectors has been thought to be secondary to active dissemination of the louse-borne disease in the human population3. Ormsbee concluded that livestock and the equivalent wild species were unlikely to be important in the ecology of epidemic typhus4. This disease was last reported in the eastern United States in Philadelphia in 1836 (ref. 5). We have now isolated six strains of R. prowazekii from the eastern flying squirrel (Glaucomys volans volans). This finding suggests that an extrahuman reservoir of epidemic typhus can exist in a species of wild rodent independent of the recent occurrence of epidemic or sporadic disease.
The effect of ambient illumination on delayed-matching and delayed-response deficits from cooling dorsolateral prefrontal cortex

The possibility was examined that the delay-dependent increase in delayed matching-to-sample (DMS) and delayed-response (DR) errors induced by prefrontal cooling (FC) could be modified by changes in ambient illumination. Monkeys were tested in normal room lighting and in the dark with intratrial delays of 1–32 sec during FC and normal brain temperature (no cooling, NC). The results showed that FC increased errors and motor activity on trials with long intratrial intervals but had little effect with short delays. Ambient illumination had little effect during either FC or NC. The results are discussed in terms of relative differences in novelty of lighting or darkness with respect to the level of illumination during training.
Moisture content and nutrition as selection forces for emerald ash borer larval feeding behaviour

The exotic phloem-feeding emerald ash borer (EAB), Agrilus planipennis, has killed tens of millions of North American ash trees (Fraxinus) since its first detection in the U.S.A. in 2002. Ash trees are killed by larval feeding in the cambial region, which disrupts translocation of photosynthates and nutrients. We observed that EAB larvae feed predominantly downwards in naturally grown green ash trees, a behaviour confirmed in greenhouse-grown black ash seedlings. Furthermore, biomass of larvae feeding downwards was greater than that for larvae feeding upwards. We sought to determine the relative importance of four selection forces (i.e. gravity, moisture content, plant defence, and nutrition) in driving this downward feeding behaviour in this study. The gravity and plant defence (i.e. polyphenols) hypotheses were ruled out because even when seedlings were grown upside down, more EAB larvae moved upwards (towards the root area), and phloem tissue below the feeding site contained higher concentrations of defensive compounds than that above the feeding site.
Distribution of T1, Q, Pegasus and mariner transposable elements on the polytene chromosomes of PEST, a standard strain of Anopheles gambiae

The chromosomal locations of four families of transposable elements, T1, Q, Pegasus and mariner, have been determined by in situ hybridization to polytene chromosomes of ovarian nurse cells of the mosquito Anopheles gambiae. As part of this effort, we have developed a vigorous pink-eyed laboratory strain of A. gambiae (PEST), rendered homozygous standard for chromosomal inversions on all autosomes. Ten different individuals of this strain were studied with each transposable element probe. The average number of hybridization sites per genome was 83.9 for T1, 63.4 for Q, 31.5 for Pegasus and 64.7 for mariner, excluding pericentric and centromeric regions. However, some degree of polymorphism was observed within each family such that, considering all ten individuals, 94 different sites were detected for T1, 82 sites for Q, 45 sites for Pegasus and 71 sites for mariner. The mean occupancy per site varied from 0.70 (Pegasus) to 0.91 (mariner), which, while significantly higher than that seen for transposable elements in natural populations of Drosophila melanogaster, is comparable to that seen in established laboratory stocks. In addition, these element families were not randomly distributed. All but Pegasus were concentrated in centromeric heterochromatin and centromere-proximal euchromatin, most showed a deficit of hybridization sites in the distal section of chromosomes, and a significant proportion of sites were coincident between families. These results provide the first detailed examination of the cytogenetic location of transposable elements in a nondrosophilid insect, and, through comparison with the behavior of transposable elements in Drosophila, may provide insight into the interaction between elements and host. The mapped elements are also expected to serve as landmarks useful in integrating the developing
Interactions between weeds and cultivated plants as related to management of plant pathogens

Abstract Weeds and native plants should be considered when endeavoring to manage and control plant pathogens of cultivated plants. Whether as a pest itself, vector of a pathogen, or reservoir of a pathogen or its vector, weeds can significantly influence disease incidence. The relationship between these factors plays a critical role in determining disease incidence and impact. Weeds can interact with pathogen management in several ways, including provision of weed biological control, parasitic weeds can directly serve as vectors of plant pathogens, weeds can serve as reservoir alternative hosts for pathogens and vectors, weeds may be obligate alternate hosts for some pathogens, and herbicides used for weed control can interact with plant pathogens. A recent concern is the advent and deployment of plants genetically engineered for pathogen resistance, raising the question of “super weeds” resulting from genetic drift of genes from crops into surrounding weed populations, the impact of which has yet to be d...
An Immediate Increase in Calcium Accumulation by Rat Thymocytes Induced by Triiodothyronine: Its Role in the Subsequent Metabolic Responses

In previous studies we have shown that the thyroid hormone T3 induces a prompt increase in the cAMP concentration of rat thymocytes in vitro. This is followed by and very likely leads to an increase in cellular uptake of the glucose analog 2-deoxyglucose (2-DG). Since these effects of T3 were shown to require the presence of Ca2+ in the suspending medium, it seemed reasonable to determine whether T3 would influence the metabolism of calcium itself. In standard medium containing 1 mM Ca2+ and 45Ca as a tracer, T3 induced a very prompt, dose-related, but transient, increase in thymocyte calcium accumulation. This effect was evident within the first minute after the addition of T3 (including processing time) and is to our knowledge the most rapid effect of T3 yet demonstrated. The effect reached a maximum very shortly thereafter and then abated within a few minutes. Uptake of 45Ca from Ca2+-free medium (5 microM Ca2+ as a contaminant) was also increased by T3, but under these conditions, the increase was sustained for the entire 120-min period of study. At a concentration of 25 microM, lanthanum (La3+) unexpectedly produced a rapid and marked (4- to 6-fold) increase in 45Ca accumulation in the thymocytes. The increase in cellular calcium accumulation produced by La3+ was not associated with any effect on thymocyte cAMP concentration or 2-deoxyglucose (2-DG) uptake. However, La3+ potentiated the response of the cell to T3 in respect to calcium accumulation, cAMP concentration, and 2-DG uptake, shifting the dose-response curve of the latter two effects to the left. In view of the calcium dependence of the T3 effect on thymocyte cAMP concentration and 2-DG uptake, and the effect of La3+ to concomitantly enhance the sensitivity of the cell to the effects of T3 on calcium accumulation and cAMP and 2-DG metabolism, we suggest that the prompt increase in cellular Ca2+ uptake induced by T3 that we demonstrated is causally related to its subsequent effect on cellular cAMP concentration and 2-DG uptake.
The influence of park access during drought on attitudes toward wildlife and lion killing behaviour in Maasailand, Kenya

Minimizing the inherent conflict between protecting fauna and flora and accommodating the needs of the local communities is one of the greatest challenges facing protected area (PA) management in developing countries of the world. Allowing pastoralists access to PAs and their resources remains a contentious issue in southern Kenya, where retaliatory killing of African lions (Panthera leo) by Maasai pastoralists has caused a steep decline in the lion population, threatening local extinction. Previous studies that have shown that local people often have negative attitudes toward PAs; here PA policy during times of hardship is linked to attitudes toward lions and behavioural intentions. Different access policies to grazing inside Tsavo and Nairobi National Parks during the 2008/2009 drought influenced Maasai attitudes toward lions and their propensity to kill them. A semi-structured questionnaire (n = 206) and a multivariate model examine the relative importance of PA access and 11 additional predictors on individuals’ attitudes and reported inclination to kill lions. Access for livestock to PAs, benefits from wildlife and higher education were associated with positive attitudes toward lions and a lower reported propensity to kill. The success of lion conservation in Maasailand may depend upon recognizing and accommodating pastoralists’ inherent vulnerability to drought-induced livestock mortality.
Interface-limited injection in amorphous organic semiconductors

We examine electron transport in the archetype amorphous organic material tris(8-hydroxyquinoline) aluminum $({\mathrm{Alq}}_{3}).$ It is established that for Al, LiF/Al, and Mg:Ag cathodes, injection processes at the metal/organic contact dominate the current-voltage characteristics. We find that transport is also injection-limited at low temperatures, but that the cathode dependence of current-voltage characteristics at $T=30$ K is substantially reduced, raising doubts over metal-to-organic injection models that depend on the cathode work function. Given that ultraviolet photoelectron spectroscopy measurements show a shift in the vacuum potential at the metal/${\mathrm{Alq}}_{3}$ interface of \ensuremath{\sim}1 eV, we investigate the impact of interfacial dipoles on adjacent molecules in the organic film. Consequently, we propose that injection is limited by charge hopping out of interfacial molecular sites whose energy distribution is broadened by local disorder in the interfacial dipole field. We derive a general analytic model of injection from interfacial states and find that it accurately predicts the current-voltage characteristics of transport in ${\mathrm{Alq}}_{3}$ over many orders of magnitude in current and over a wide range of temperatures. The model is extended to other amorphous organic semiconductors and is found to be applicable to both polymers and small molecular weight organic compounds.
Hyperglycemia and Incidence of Frailty and Lower Extremity Mobility Limitations in Older Women

mately three-times greater risk of incident frailty and three to five times greater risk of lower extremity mobility limitations (all P < .05). In fully adjusted models, HbA1c of 8.0% or greater (vs < 5.5%) was associated with incident frailty (hazard ratio (HR) = 3.33, 95% confidence interval (CI) = 1.24–8.93), walking difficulty (HR = 3.47, 95% CI = 1.26–9.55), low walking speed (HR = 2.82, 95% CI = 1.19–6.71), and low physical performance (HR = 3.60, 95% CI = 1.52–8.53). CONCLUSION: Hyperglycemia is associated with the development of frailty and lower extremity mobility limitations in older women. Future studies should identify mediators of these relationships. J Am Geriatr Soc 60:1701– 1707, 2012.
Mass spectrometry in the development of drugs from traditional medicines

The mass spectrometer ionizes molecules to separate and weigh the resulting molecular ions and their dissociation products. These product masses indicate directly the sequence of constituents of the original molecule, such as amino acids in proteins or bases in nucleotides. Because single ions can be detected, even subfemtomole sensitivities are possible. In tandem mass spectrometry (MS/MS), molecular ions from a mixture can be separated to isolate ions of a specific component, whose further dissociation can then give structural information on that component. Electrospray ionization and other recently developed methods make possible the ionization of biomolecules even larger than 100 kDa. The Fourier-transfer mass spectrometer has unusual capabilities for measuring ions over a 100 kDa mass range simultaneously at unit resolution for MS/MS applications utilizing subfemtomole sample quantities.
F2, H2O, and O2 etching rates of diamond and the effects of F2, HF and H2O on the molecular O2 etching of (110) diamond

Abstract Oxidation kinetics of natural (110) diamond by oxygen and water were investigated using in situ Fizeau interferometry. Apparent activation energies of 53 and 26 kcal mol −1 were obtained for the etching of (110) type Ia diamond by O 2 and H 2 O respectively. The etch rate was found to follow second-order kinetics with respect to O 2 pressure in the pressure range 0.04–10 Torr. For water over the vapour pressure range 0.1–2 Torr, the reaction has a reaction order near unity. The diamond (110) surface was impervious to etching by molecular fluorine at all temperatures up to 1300 °C. Fluorine, hydrogen fluoride and water were found to inhibit the molecular oxygen etching of diamond. Below 900 °C, oxidation is inhibited by the addition of F 2 and HF presumably by blocking reactive sites on the diamond surface through formation of CF bonds. Above 900 °C, the fluorine is thought to desorb from the diamond (110) surface, rendering the surface susceptible to further oxidation. Addition of water below 800 °C was found to retard etching by molecular oxygen. This is attributed to the formation of COH bonds, analogous to CF.
An Institutional Perspective on Student Business Plan Competitions

As the number of business plan competitions (BPC) and in particular student business plan competitions (SBPC) has been growing over the last 30 years, there is a general assumption that the competi...
Hyperthermic therapy for human neoplasms: Thermal death time

Hyperthermia greater than or equal to 42 C is tumoricidal, apparently a function of absolute temperature and duration of heating. However, because the technology for producing safe and effective deep hyperthermia did not exist, there was virtually no data on the thermal death times of human cancers. The development of a fundamentally new radio frequency device that produces uniform hyperthermia to any depth without surface tissue injury has allowed preliminary testing of this hypothesis in 38 patients with advanced cancer. Temperature measurements were taken in tumors and normal adjacent tissues. Tumors were heated from 40 C to greater than or equal to 50 C, one to ten times (13-600 minutes). Serial tumor biopsies compared percent necrosis (total absence of nuclei) by type of therapy. Of 44 tumors evaluated (21 superficial, 23 visceral), 31 (70%) were heated greater than or equal to 42 C, 23 (52%) greater than or equal to 45 C, and 14 (32%) greater than or equal to 50 C, with virtually no normal tissue injury. Single, short duration hyperthermia at greater than or equal to 50 C resulted in 20-100% tumor necrosis, while lower temperatures had no effect. Two or three treatments at 45-50 C produced 70-100% necrosis, while lower temperatures produced less necrosis at more than twice the duration of heating. Multiple treatments produced increased necrosis at lower temperatures; however, at the same temperature duration, higher temperatures were most effective. These clinical results support the hypothesis that the observed necrosis is related to both temperature and treatment time and suggest that higher temperatures and longer durations of therapy are most beneficial.
Nonrandom amino acid substitution and estimation of the number of nucleotide substitutions in evolution

A method of estimating the number of nucleotide substitutions from amino acid sequence data is developed by using Dayhoff's mutation probability matrix. This method takes into account the effect of nonrandom amino acid substitutions and gives an estimate which is similar to the value obtained by Fitch's counting method, but larger than the estimate obtained under the assumption of random substitutions (Jukes and Cantor's formula). Computer simulations based on Dayhoff's mutation probability matrix have suggested that Jukes and Holmquist's method of estimating the number of nucleotide substitutions gives an overestimate when amino acid substitution is not random and the variance of the estimate is generally very large. It is also shown that when the number of nucleotide substitutions is small, this method tends to give an overestimate even when amino acid substitution is purely at random.
Vascular smooth muscle migration and proliferation in response to lysophosphatidic acid (LPA) is mediated by LPA receptors coupling to Gq.

Many G protein-coupled receptors can couple to multiple G proteins to convey their intracellular signaling cascades. The receptors for lysophosphatidic acid (LPA) possess this ability. LPA receptors are important mediators of a wide variety of biological actions including cell migration, proliferation and survival which are processes that can all have a considerable impact on vascular smooth muscle (VSM) and blood vessels. To date, confirmation of G proteins involved has mostly relied on the inhibition of Gi-mediated signaling via pertussis toxin (PTx). We were interested in the specific involvement of LPA-Gq-mediated signaling therefore we isolated aorta VSM cells (VSMCs) from transgenic mice that express a peptide inhibitor of Gq, GqI, exclusively in VSM. We detected both LPA1 and LPA2 receptor expression in mouse VSM whereas LPA1 and LPA3 were expressed in rat VSM. SM22-GqI did not alter LPA-induced migration but it was sufficient to attenuate LPA-induced proliferation. GqI expression also attenuated LPA-induced ERK1/2 and Akt activation by 40–50%. To test the feasibility of this peptide as a potential therapeutic agent, we also generated adenovirus encoding the GqI. Transient expression of GqI was capable of inhibiting both LPA-induced migration and proliferation of VSMCs isolated from rat and mouse. Furthermore, ERK activation in response to LPA was also attenuated in VSMCs with Adv-GqI. Therefore, LPA receptors couple to Gq in VSMC and mediate migration and proliferation which may be mediated through activation of ERK1/2 and Akt. Our data also suggest that both chronic and transient expression of the GqI peptide is an effective strategy to lower Gq-mediated LPA signaling and may be a successful therapeutic strategy to combat diseases with enhanced VSM growth such as occurs following angioplasty or stent implantation.
Current concepts: Vater and other associations: Historical perspectives and modern interpretations

Associations are statistically related groups of anomalies, and the VATER association probably is the best known example. The concept is widely used, but there are difficulties with both definition and delineation. An historical review is used to define implicit commonalities of associations. These commonalities are then used to develop a testable model which defines associations as derivatives of nonspecific teratologic events acting on developmental fields. Findings depend on the timing, location, and magnitude of these events, and reflect developmental constraints. This clarifies the nature of associations and provides guidelines for their study and use.
1993 William J. Stickel Gold Award. Stability of absorbable fixation in basilar first metatarsal osteotomies

The purpose of this study was to compare the structural characteristics of 2.0-mm polyglycolic acid pins and 2.0-mm Steinmann pins in oblique closing base wedge osteotomies of the first metatarsal bone commonly used to correct metatarsus primus varus. Six pairs of fresh frozen cadaveric first metatarsal bones were osteotomized, fixated with either absorbable or stainless steel 2.0-mm pins, cemented in a specimen-holding jig, and tested with the Bionix Material Testing System. There was no significant difference in the mean ultimate force, ultimate displacement, or structural stiffness when comparing 2.0-mm polyglycolic acid pins and Steinmann pins in this model. The structural characteristics of 2.0-mm absorbable pins were the same as stainless steel pins at the time of initial placement in the oblique closing base wedge osteotomy of the first metatarsal.
Enabling systems thinking to accelerate the development of senior systems engineers

As systems become more complex, the roles involved in developing and managing such systems also become more complex. Thus, there is increasing interest in educating and training engineering professionals to think more systemically. In particular, there is an increasing need to accelerate the development of senior systems engineers. As new educational degree programs in systems rapidly emerge and as companies scurry to establish systems training programs to meet this need, fundamental questions still remain about how systems thinking develops in engineers. Increased understanding of the mechanisms that develop systems thinking will enable effective and efficient development of senior systems professionals. After reviewing related literature, an exploratory and inductive study was designed to gather data on enablers, barriers, and precursors to systems thinking development in engineers. In a field study conducted primarily in the United States aerospace sector, 205 interviews were conducted in 10 host companies. Senior systems engineers were studied to better understand how they developed systems thinking, and information was collected on company procedures for developing systems engineers. Using interview and survey data, comparisons were made of two control groups and senior systems engineers. Proven stellar systems thinkers were also interviewed. To summarize the results, even though systems thinking definitions diverge, there is consensus on primary mechanisms that enable or obstruct systems thinking development in engineers. In order to reconcile the divergent definitions observed, a systems thinking framework and definition are given. The data show that the primary mechanisms that enable systems thinking development include experiential learning, specific individual characteristics, and a supporting environment. This document defines the research space on this topic and suggests applications for the results. Better understanding of systems thinking development provides a foundation for educational interventions and employee development in systems thinking for engineering professionals across industry, government, and academia. © 2007 Wiley Periodicals, Inc. Syst Eng The Massachusetts Institute of Technology (M.I.T.) is the copyright owner of the original dissertation work on which this paper is based. Permission has been granted to the authors to reproduce this work for publication in the Systems Engineering journal by Wiley. The research was sponsored by the Lean Aerospace Initiative at MIT. For more information, contact the corresponding author Heidi L. Davidz.
Exchange rate expectations in dual exchange markets

Abstract This paper develops and examines a model of a small country operating a dual exchange market system. Particular attention is paid to the rational formation of expectations of the financial market exchange rate. In the context of the present model, it is shown that rational expectations of the financial rate are formed in a manner exactly opposite to previously assumed expectations behavior.
Effects of pergolide on sensorimotor gating of the startle reflex in rats.

Rationale: Prepulse inhibition (PPI), a cross-species measure of sensorimotor gating, is impaired in certain neuropsychiatric disorders, including schizophrenia. This study was designed to assess the effects of the D2-family agonist pergolide in rats, in anticipation of human studies of the dopaminergic regulation of PPI. Methods: The effects of pergolide (0.0001–0.5 mg/kg) on PPI of the acoustic startle reflex were studied in rats using a wide range of prepulse intensities [1–15 dB(A) over background] and prepulse intervals (5–100 ms, onset to onset). Studies also examined the effects of the D2 antagonist haloperidol on pergolide-induced changes in PPI. Results: Pergolide exhibited dose- and stimulus-dependent effects on PPI. Pergolide increased PPI when startle stimuli were preceded by weak prepulses [1–5 dB(A) over background] at the longest prepulse interval (100 ms), or intense prepulses [15 dB(A) over background] at short prepulse intervals (5–20 ms). Pergolide (0.5 mg/kg) also decreased PPI elicited by intense prepulses at long intervals (60–100 ms). Both PPI-enhancing and PPI-disruptive effects of pergolide were reversed by the D2 antagonist haloperidol. Conclusions: These effects of pergolide suggest that D2 substrates mediate opposing influences on PPI under different stimulus conditions. The dopaminergic regulation of sensorimotor gating appears to interact with stimulus characteristics such as relative intensity and temporal separation, allowing for dynamic shifts in both the quantity and quality of "gated" information.
Comentario: el estado actual de la psicofarmacología y la psiquiatría

La psiquiatria clinica moderna ha pasado a estar dominada por la psicofarmacologia a multiples niveles a lo largo de las ultimas decadas, tras una epoca de hegemonia psicodinamica en muchos paises. La inauguracion de una importante revista de psiquiatria internacional, la Revista de Psiquiatria y Salud Mental espanola, nos brinda la oportunidad de analizar el estado actual de la psiquiatria en relacion con la psicofarmacologia. El inicio de la psicofarmacologia moderna puede fecharse en el momento de la reintroduccion del carbonato de litio (utilizado anteriormente para tratar la gota) en la medicina clinica para el tratamiento y la prevencion de la mania por parte de John Cade en Melbourne en 1949, o en los descubrimientos iniciales de los efectos antimaniacos y antipsicoticos de clorpromazina en Paris por Pierre Deniker et al en 1952. El farmaco neuroleptico-antipsicotico clorpromazina y sus multiples analogos quimicos aparecidos en los anos cincuenta y sesenta del pasado siglo procedian de agentes antihistaminicos-sedantes conocidos desde finales de la primera decada del siglo xix. Esto constituyo una importante contribucion de la tecnologia quimica y farmaceutica, pero tambien intervino en ello la observacion clinica casual. Su descubrimiento condujo finalmente al desarrollo de los antidepresivos, empezando con la imipramina a finales de los anos cincuenta, y de los farmacos antipsicoticos de segunda generacion («atipicos»), el primero de los cuales fue la clozapina, en 1960. Ambos farmacos diferian de los neurolepticos triciclicos por tener un anillo central
Pentacene-based organic thin-film transistors

Organic thin-film transistors using the fused-ring polycyclic aromatic hydrocarbon pentacene as the active electronic material have shown mobility as large as 0.7 cm/sup 2//V-s and on/off current ratio larger than 10/sup 8/; both values are comparable to hydrogenated amorphous silicon devices. On the other hand, these and most other organic TFT's have an undesirably large subthreshold slope. We show here that the large subthreshold slope typically observed is not an intrinsic property of the organic semiconducting material and that devices with subthreshold slope similar to amorphous silicon devices are possible.
Complexity Analysis of The GAO Algorithm

In this paper, we investigate the complexity of the Gao algorithm for decoding Reed-Solomon (RS) codes. We study both direct and fast implementations of the Gao algorithm and compare their complexities to those of traditional syndrome-based decoding algorithms. Our results show that, regardless of the implementation, the Gao algorithm has higher complexity than syndrome-based decoding algorithms for high rate RS codes that are used in practice.
PERPETRATORS' AND SERVERS' RESPONSIBILITY AND PUNISHMENT FOR DRUNK-DRIVING OUTCOMES

Observers (N = 169) were presented written descriptions of alcohol-related motor vehicle incidents that varied according to severity of outcome, blood alcohol level (BAL) of the perpetrator, and prevailing road conditions. Observers made attributions of responsibility and recommendations for punishment for both perpetrator and alcohol server. Severity-dependent effects were obtained for perpetrators' punishment but relatively high levels of responsibility were assigned to the perpetrator across outcomes, and observers did not differentiate between accident and apprehension outcomes in attributing responsibility. BAL affected perpetrators' punishment but not responsibility, while adverse road conditions produced the opposite pattern of results. In general, relatively low levels of responsibility and punishment were assigned to the server, but both measures were influenced by road conditions, primarily at the intermediate BAL. The divergent findings for responsibility and punishment are discussed. Language: en
Functional Genetic and Biophysical Analyses of Membrane Disruption by Human Adenovirus

The identification of the adenovirus (AdV) protein that mediates endosome penetration during infection has remained elusive. Several lines of evidence from previous studies suggest that the membrane lytic factor of AdV is the internal capsid protein VI. While these earlier results imply a role for protein VI in endosome disruption, direct evidence during cell entry has not been demonstrated. To acquire more definitive proof, we engineered random mutations in a critical N-terminal amphipathic α-helix of VI in an attempt to generate AdV mutants that lack efficient membrane penetration and infection. Random mutagenesis within the context of the AdV genome was achieved via the development of a novel technique that incorporates both error-prone PCR and recombineering. Using this system, we identified a single mutation, L40Q, that significantly reduced infectivity and selectively impaired endosome penetration. Furthermore, we obtained biophysical data showing that the lack of efficient endosomalysis is associated with reduced insertion of the L40Q mutation in protein VI (VI-L40Q) into membranes. Our studies indicate that protein VI is the critical membrane lytic factor of AdV during cellular entry and reveal the biochemical basis for its membrane interactions.
The rat gut micronucleus assay: A good choice for alternative in vivo genetic toxicology testing strategies

The in vivo bone marrow (BM) micronucleus assay is one of the three tests in the standard test battery to assess the genotoxic potential of a pharmaceutical candidate. In some cases, depending on results of in vitro studies, the route of administration or the degree of systemic exposure, in vivo assessment of genotoxicity in the BM alone may not be sufficient. Based on the potential for high gut exposures to orally administered compounds with low systemic exposures as well as the potential susceptibility of rapidly dividing cells of the intestinal tissues, we have developed a modified technique for evaluating micronuclei formation in both the duodenum and colon of rats based on earlier publications. Adult male Sprague Dawley rats were treated once daily for 2 days with either vehicle control or with the test articles acetyl salicylic acid (ASA), carbendazim (CAR), cyclophosphamide (CP), dimethylhydrazine (DMH), mitomycin C (MMC) or vinblastine sulfate (VIN). The duodenum, colon, and BM were harvested, processed, and analyzed for micronucleus induction. Results from these studies demonstrated differences in the susceptibility for different test compounds in the three tissues tested. When MMC and VIN were dosed by different routes at the same dose levels both compounds produced positive results in all three tissues by intraperitoneal injection but not oral administration. These studies suggest that overall the GI micronucleus assay might be a useful tool for clastogenic and aneugenic compounds that are expected to produce high sustained concentrations in the gastrointestinal tract with little systemic exposure.
An Assessment of a Self-Directed Learning Approach in a Graduate Web Application Design and Development Course

Research has shown that adult learners have a strong desire for a self-directed and autonomous learning experience. This paper presents an evaluation of an approach to supporting self-directed learning employed in a graduate-level Web application design and development course. The approach allows students to define and develop semester-long team projects in an independent fashion including the definition of their own grading metric and the evaluation of themselves against the measure. This paper presents the results of a survey on student opinion of the self-directed learning approach and an evaluation of grades. Study results indicate that the self-directed learning approach used in the course was quite successful in providing adult students with an autonomous and self-directed learning experience
Last Hired, First Fired? Unemployment and Urban Black Workers During the Great Depression

Throughout the Great Depression, the unemployment rates of blacks exceeded those of whites in urban areas of both North and South. Among men, this difference was largely due to racial differences in occupational status, whereas among women, unemployment rates were dramatically higher for blacks even within specific occupations. The occupational pattern of the unemployment gap suggests that labor market discrimination played a role, especially in unskilled service jobs.
Empirical Examination of the Factors Regulating Thunderstorm Initiation

AbstractInitiation is the part of the convective life cycle that is currently least understood and least well forecast. The inability to properly forecast the timing and/or location of deep convection initiation degrades forecast skill, especially during the warm season. To gain insight into what atmospheric parameters distinguish areas where storms initiate from areas where they do not initiate, over 55 000 thunderstorm initiation points over the central United States from 2005 to 2007 are found and a number of thermodynamic and kinematic parameters are computed from 20-km Rapid Update Cycle (RUC)-2 data. In addition to the initiation points, data are also collected at nearby locations where thunderstorms did not initiate (null points) for comparison. Thunderstorm identification and tracking are done using several tools within the Warning Decision Support Services–Integrated Information (WDSS-II) package and a thunderstorm tracking algorithm called Thunderstorm Observation by Radar (ThOR). The parameters...
On the Need to Compensate for Edema-Induced Dose Reductions in Preplanned 131Cs Prostate Brachytherapy

Purpose Surgical trauma-induced edema and its protracted resolution can lead to significant dose reductions in preplanned 131 Cs prostate brachytherapy. The purpose of this work was to examine whether these dose reductions should be actively compensated for and to estimate the magnitude of the additional irradiation needed for dose compensation. Methods and Materials The quantitative edema resolution characteristics observed by Waterman et al. were used to examine the physical and radiobiologic effects of prostate edema in preplanned 131 Cs implants. The need for dose compensation was assessed using the dose responses observed in 125 I and 103 Pd prostate implants. The biologically effective dose, calculated with full consideration of edema evolution, was used to estimate the additional irradiation needed for dose compensation. Results We found that the edema-induced dose reduction in preplanned 131 Cs implants could easily exceed 10% of the prescription dose for implants with moderate or large edema. These dose reductions could lead to a >10% reduction in the biochemical recurrence-free survival for individual patients if the effect of edema was ignored. For a prescribed dose of 120 Gy, the number of 2-Gy external beam fractions needed to compensate for a 5%, 10%, 15%, 20%, and 25% edema-induced dose reduction would be one, four, six, seven, and nine, respectively, for prostate cancer with a median potential doubling time of 42 days. The required additional irradiation increased for fast-growing tumors and/or those less efficient in sublethal damage repair. Conclusion Compensation of edema-induced dose reductions in preplanned 131 Cs prostate brachytherapy should be actively considered for those implants with moderate or large edema.
Calcification of Advanced Atherosclerotic Lesions in the Innominate Arteries of ApoE-Deficient Mice: Potential Role of Chondrocyte-Like Cells

Objective— Advanced atherosclerotic lesions in the innominate arteries of chow-fed apolipoprotein E–deficient mice become highly calcified with 100% frequency by 75 weeks of age. The time course, cell types, and mechanism(s) associated with calcification were investigated. Methods and Results— The deposition of hydroxyapatite is preceded by the formation of fibro-fatty nodules that are populated by cells that morphologically resemble chondrocytes. These cells are spatially associated with small deposits of hydroxyapatite in animals between 45 and 60 weeks of age. Immunocytochemical analyses with antibodies recognizing known chondrocyte proteins show that these cells express the same proteins as chondrocytes within developing bone. Histological and electron microscopic analyses of lesions from animals between 45 and 60 weeks of age show that the chondrocyte-like cells are surrounded by dense connective tissue that stains positive for type II collagen. Nanocrystals of hydroxyapatite can be seen within matrix vesicles derived from the chondrocyte-like cells. In mice between 75 and 104 weeks of age, the lesions have significantly reduced cellularity and contain large calcium deposits. The few remaining chondrocyte-like cells are located adjacent to or within the large areas of calcification. Conclusions— Calcification of advanced lesions in chow-fed apolipoprotein E–deficient mice occurs reproducibly in mice between 45 and 75 weeks of age. The deposition of hydroxyapatite is mediated by chondrocytes, which suggests that the mechanism of calcification may in part recapitulate the process of endochondral bone formation.
Evidence for force-feedback inhibition in chronic stroke

The presence of force-feedback inhibition was explored during reflex responses in five subjects with known incidence of stroke. Using constant velocity stretches, it was previously found that after movement onset, active reflex force progressively increases with increasing joint angle, at a rate proportional to a fractional exponent of the speed of stretch. However, after the reflex force magnitude exceeds a particular level, it begins rolling off until maintaining a steady-state value. The magnitudes of these force plateaus are correlated with the speed of stretch, such that higher movement speeds result in higher steady-state forces. Based upon these previous studies, we hypothesized that force plateau behavior could be explained by a force-feedback inhibitory pathway. To help facilitate an understanding of this stretch reflex force roll off, a simple model representing the elbow reflex pathways was developed. This model contained two separate feedback pathways, one representing the monosynaptic stretch reflex originating from muscle spindle excitation, and another representing force-feedback inhibition arising from force sensitive receptors. It was found that force-feedback inhibition altered the stretch reflex response, resulting in a force response that followed a sigmoidal shape similar to that observed experimentally. Furthermore, simulated reflex responses were highly dependent on force-feedback gain, where predicted reflex force began plateauing at decreasing levels with increases in this force-feedback gain. The parameters from the model fits indicate that the force threshold for force-sensitive receptors is relatively high, suggesting that the inhibition may arise from muscle free nerve endings rather than Golgi tendon organs. The experimental results coupled with the simulations of elbow reflex responses suggest the possibility that after stroke, the effectiveness of force-feedback inhibition may increase to a level that has functional significance. Practical implications of these findings are discussed in relation to muscle weakness commonly associated with stroke.
Association Between Underinsurance and Access to Care Among Children With Special Health Care Needs in the United States

Objective. To examine the impact of un- derinsurance on access to care among children with spe- cial health care needs (CSHCN) in the United States. Methods. Interviews were conducted by telephone with the families of 38 866 CSHCN who were younger than 18 years using the 2001 National Survey of Children With Special Health Care Needs. The prevalence of un- derinsurance and its relationship to access to care and family financial problems was examined in this cross- sectional analysis. CSHCN were classified as underin- sured when coverage was deemed inadequate to meet the child's needs. Results. An estimated 12.8% of US children experi- enced a special health care need in 2001. Although 95% of CSHCN had some type of insurance coverage at the time of the interview, 32% were classified as underinsured. Underinsured CSHCN were disproportionately repre- sented in low-income families and were significantly more likely than fully insured children to have unmet health needs, and their families were more likely to report difficulty in obtaining specialty referrals, experi- ence financial problems, and report that the child's con- dition caused family members to reduce or stop work. Underinsured CSHCN seemed to be somewhat better off than CSHCN with no insurance coverage on these mea- sures. Conclusions. Underinsured CSHCN represent an im- portant and largely hidden underserved population. Pe- diatrics 2005;116:1162-1169; children with special health care needs, disability, national estimates, insurance, un- derinsurance, access to care.
Improving outcomes in heart transplantation: The potential of proliferation signal inhibitors

Graft failure and mortality among heart transplant recipients remains higher than in populations receiving renal transplants. A major cause of graft loss is cardiac allograft vasculopathy (CAV), a condition characterized by diffuse thickening of coronary blood vessels. CAV often progresses silently, with major cardiac events (eg, ventricular arrhythmia) being the first presentation. Better diagnosis and monitoring of CAV is now possible with intravascular ultrasonography, a sensitive technique for measuring intimal thickness. To date, immunosuppressants have shown little efficacy for preventing CAV. However, a new class of agents, proliferation signal inhibitors (sirolimus and everolimus), have shown considerable efficacy in this regard and for preventing rejection. In an open-label trial, sirolimus therapy was associated with less intimal and medial proliferation than azathioprine. More robust evidence is available from a larger-scale, double-blind trial involving everolimus. At 12-month follow-up the incidence of CAV was significantly lower in patients receiving everolimus (35.7% and 30.4% for everolimus 1.5 and 3.0 mg/d vs 52.8% for azathioprine; P < .05). Sirolimus and everolimus were also associated with a lower rate of cytomegalovirus infection. As with other immunosuppressants, these agents are associated with adverse events (eg, hyperlipidemia), but they can be managed. Coadministration with calcineurin inhibitors (CNIs) can exacerbate CNI-related nephrotoxicity, but evidence suggests that everolimus administered with reduced-exposure cyclosporine in the maintenance phase preserves renal function without loss of immunosuppressive efficacy. Reduced CNI dosing in de novo patients is also a potential future benefit. Proliferation signal inhibitors have considerable potential for improving outcomes in heart transplantation.
Electronic Structure and Total Energy of Crystalline Approximants to Quasicrystalline Al-Cu-Fe Alloys

We have performed self-consistent band structure calculations by the augmented plane wave method within the local density approximation for crystalline approximants to quasicrystalline Al-Cu-Fe alloys. These calculations are done for eight atom supercells with bcc symmetry. The calculated total energies, density of states and xray emission spectra are compared with experiment.
Comparison of two bioelectrical impedance analysis models for total body water measurement in children

SummaryWe compared two bioelectrical impedance analysis models, the right-sided tetrapolar method and an experimental cylindrical method, to total body water (TBW) determined by isotopic dilution in 37 prepubertal children aged 5–9 years, who were divided into development and cross-validation groups. Despite its theoretical advantage, no improvement in predicted TBW was seen with the experimental method. The best predictive equation, using the tetrapolar method, was TBW (kg) = 1·84 + 0·45 (height squared/resistance) + 0·11(weight); r2 = 0·98; SEE = 0·62 kg.
Mycoplasma genitalium Infections in Asymptomatic Men and Men with Urethritis Attending a Sexually Transmitted Diseases Clinic in New Orleans

We report the results of a study of Mycoplasma genitalium (detected with a modified polymerase chain reaction [PCR] assay) in men with urethritis and in asymptomatic control subjects at a sexually transmitted diseases clinic in New Orleans. Data for 97 men with urethritis and 184 asymptomatic men were available for analysis. M. genitalium infection rates in symptomatic and asymptomatic men who were negative for Chlamydia trachomatis and Neisseria gonorrhoeae were 25% and 7%, respectively (P = .006). M. genitalium coinfection rates among men with chlamydial and gonococcal urethritis were 35% and 14%, respectively. Men with M. genitalium urethritis resembled those with C. trachomatis in that both groups were younger and more likely to experience milder urethral symptoms. Among men with urethritis, the sensitivities of PCR of urine and swab specimens for the detection of M. genitalium were 87% and 91%, respectively. M. genitalium is associated with nongonococcal urethritis in this population.
User generated video annotation using Geo-tagged image databases

In this paper we propose a system that annotates a user generated video based on the associated location metadata, by exploiting user-tagged image databases. An example of such a database is a photo sharing website such as Flickr [1] where users upload their images and annotate them with various tags. The goal is to find the tags that have high probability of being relevant to the video without any complex object or action recognition being done to the video sequence. A video is first segmented into camera views and a set of keyframes are selected to represent the video. We will describe the concept of camera view as the basic element of user generated videos which has special properties suitable for the video annotation application. The keyframes are used to retrieve the most relevant images in the database. A “tag processing” step is then used to tag the video.