Weak Results Research Articles

Ultrastructural and Immunological Characterization of Hepatitis C Core Protein-DNA Plasmid Complexes

Recently, it has been shown that a truncated HCV core (HCcAg) variant, covering the first 120 aa (HCcAg.120), interacts with plasmid DNA vaccine (pIDKE2), encoding the HCV structural proteins (HCcAg, E1 and E2). In the present work, HCcAg.120-pIDKE2 complexes, forming heterogeneous packaged structures, were visualized using a negative stain/rotary shadow technique. Interestingly, 72 hours after intramuscular injection of HCcAg.120-pIDKE2 complexes in Balb/c mice, E2 protein was immunolabeled in muscle cells. In fact, HCcAg.120-pIDKE2 complexes induced anti-HCV humoral and cellular immune responses in mice when inoculated by both, parenteral or mucosal routes, although intranasal administration generally rendered weaker results. On the other hand, data demonstrated that Alum enhanced the HCV-specific IgG antibody production. However, the analysis of the HCV-specific cellular immune response showed that HCcAg.120-pIDKE2 delivered in PBS by the intramuscular route induced the strongest HCV-specific lymphoproliferative response, especially against E1 and induced viremia control in a vaccinia virus surrogate challenge model. These results support the use of HCcAg.120-pIDKE2 complexes in the rational design of therapeutic or preventive vaccine strategies against HCV infection.

Achievement of Serbian eighth grade students in science

The paper considers the main results and some educational implications of the TIMSS 2003 assessment conducted in Serbia in the fields of the science achievement of Serbian eighth grade students and the science curriculum context of their achievement. There were 4264 students in the sample. It was confirmed that Serbian eighth graders had made average scale score of 468 points in the science, and with this achievement they are placed in the zone of the top of low international benchmarking level, very close to the point of intermediate benchmark. The average science achievement of the Serbian eighth graders is somewhat below the general international science achievement. The best results were achieved in the science content domain of "chemistry", and the lower results in the content domain of "environmental science". Across the defined science cognitive domains, it was confirmed that the Serbian students had achieved the best results in cognitive domain of "factual knowledge" and weaker results in "reasoning and analysis". The achieved results raise many questions about contents of the science curriculum in Serbia, its overall quality and basic characteristics of its implementation. These results can be eligibly used to improve the science curricula and teaching in Serbian primary school. .

Mathematics achievement of Serbian eighth grade students and characteristics of mathematics curriculum

This paper considers the main results and some educational implications of the TIMSS 2003 assessment conducted in Serbia, in the fields of mathematics achievement of Serbian eighth grade students and the mathematics curriculum context of their achievement. It was confirmed that Serbian eighth graders have made average scale score of 477 points, and with this achievement they are placed in the zone of intermediate international benchmarking level. The average mathematics achievement of the Serbian eighth graders is somewhat above the average international mathematics achievement. The best result was achieved in the content domain of "algebra", and the lower result in the content domains of "measurement" and "data". In the defined cognitive domains the Serbian students have achieved the best results in "solving routine problems" and "knowing facts and procedures", and the weaker result in "reasoning". Statistically significant difference was found in the mathematics achievement between girls and boys in the Serbian TIMSS 2003 sample, so the girls? average scale score was 480 points and the same value for the boys was 473 points. The achieved results raise many questions about the contents of mathematics curriculum in Serbia, its quality and basic characteristics of its implementation. These results can be eligibly used to improve the mathematics curriculum and teaching in Serbian primary school.

Telecommunications Policies: Measurement and Determinants

This paper presents new data on telecommunications reform for a cross section of countries. We measure telecommunications reform along two dimensions: entry barriers and regulatory independence. This data set is combined with a comprehensive set of performance, institutional and political data to analyze the determinants of telecommunications policies. We find that entry barriers are positively associated with the degree to which countries have an interventionist legal tradition, but they are unrelated to the partisan ideology of reforming governments. We also find that countries with weak protection of investors' quasi-rents by other means, and countries with a larger incumbent, are more prone to create independent regulatory agencies, although the latter is a weaker result.

A Note on the Spectrum of Invertible p-hyponormal Operators

A bounded linear operator T is clalled p-hyponormal if (T*T) p ≥ (TT) p , 0 < p < 1. It is known that for semi-hyponormal operators (p = 1/2), the spectrum of the operator is equal to the union of the spectra of the general polar symbols of the operator. In this paper we prove a somewhat weaker result for invertible p-hyponormal operators for 0 < p < 1/2.

Dermatophagoides extract-treated confluent type II epithelial cells (cA549) and human lung mesenchymal cell growth

Chronic severe persistent asthma is associated with damaged epithelial cells with discontinuous tight junctions that contribute to dysregulated fibroblast and endothelial cell (mesenchymal) growth. Dermatophagoides species-derived proteases have been shown to cause damage to epithelial cell tight junctions. To determine whether Dermatophagoides species can stimulate confluent A549 (cA549), a cell type with discontinuous tight junctions that approximate differentiated type II cells, to undergo altered growth and secrete putative soluble factors that affect the growth of human lung fibroblasts and microvascular endothelial cells. Dialyzed Dermatophagoides pteronyssinus or Dermatophagoides farinae extracts (0, 300, 600, and 1000 AU/mL) were cultured with and without cA549 in serum-free media for 24 hours. After changes in cA549 growth were recorded, conditioned media from extracts with cA549 (CM) and without cA549 (control media [CTLM]) were transferred to fibroblasts and endothelial cells for 24 hours. Fibroblast and endothelial cell growth responses to CM and CTLM were observed and measured. All conditions showed greater than 95% cell viability. Confluent A549 showed dose-dependent growth changes characterized by increased aggregation when incubated with 300, 600, and 1000 AU/mL of D pteronyssinus in serum-free media relative to control. The CM, but not the CTLM, induced dose-dependent aggregation by fibroblasts and endothelial cells. Fibroblasts also showed decreased adhesion when incubated with CM. Dermatophagoides farinae-treated cA549 showed similar but weaker results. The use of serum, boiled CM, or boiled extract inhibited these findings. Dialyzed Dermatophagoides species extracts altered cA549 growth and stimulated the secretion of factors that dysregulate mesenchymal cell growth in vitro.

The finiteness property and Łojasiewicz inequality for global semianalytic sets

Abstract We prove the finiteness property for the class of global semianalytic sets: we get it as a consequence of a global weak Łojasiewicz inequality for this class. This weaker result still implies the usual Hörmander form. Some other consequences are deduced.

Chlamydia pneumoniae and Lung Cancer: Epidemiologic Evidence

Chlamydia pneumoniae is a common cause of acute respiratory infection and has been hypothesized to cause several chronic diseases, including lung cancer. The purpose of this article is to identify, describe, and critically examine the published studies on the association between C. pneumoniae infection and risk of lung cancer. In the six studies identified, previous C. pneumoniae infection was defined on the basis of serologic criteria, which varied between studies. All studies reported elevated relative risk estimates for the association of serologic evidence of infection and risk of lung cancer. The three studies in which past infection was defined based on testing of prediagnostic blood specimens tended to have weaker results (odds ratio range, 1.2-2.1) than those based on postdiagnostic blood specimens (odds ratio range, 1.4-9.9). Selection bias, measurement error, and inadequate control for confounding are concerns in some of these studies. Nevertheless, results were relatively consistent, supporting a causal association. Inflammation caused by chronic infection with C. pneumoniae may be involved in the carcinogenic process but this relationship will be difficult to further define through serologic data. To better understand the nature of this association, both experimental study designs, such as those based on animal models or randomized controlled antibiotic treatment trials in humans, and observational study designs (e.g., studies that involve detection of C. pneumoniae in pulmonary specimens obtained before cancer onset) could be explored and may shed additional light on this important association.

BOUNDARIES OF ATTRACTORS AS OMEGA LIMIT SETS

When a system of ordinary differential equations on ℜd have an attractor [Formula: see text] given as the omega-limit set of a compact set [Formula: see text], then provided that D contains [Formula: see text] necessarily [Formula: see text], i.e. the boundary of the attractor is the omega-limit set of the boundary of D. In general only a weaker result, [Formula: see text], can be shown to hold for random attractors arising from systems of stochastic ordinary differential equations, where now D is any compact set such that [Formula: see text] is contained in D with a positive probability. However, if in addition [Formula: see text] is empty with positive probability, then in fact [Formula: see text].

PRIME DIVISORS OF SEQUENCES ASSOCIATED TO ELLIPTIC CURVES

We consider the primes which divide the denominator of the -coordinate of a sequence of rational points on an elliptic curve. It is expected that for every sufficiently large value of the index, each term should be divisible by a primitive prime divisor, one that has not appeared in any earlier term. Proofs of this are known in only a few cases. Weaker results in the general direction are given, using a strong form of Siegel's Theorem and some congruence arguments. Our main result is applied to the study of prime divisors of Somos sequences.

Démotivation et dysfonctionnements frontaux chez le sujet âgé : place de la leucoaraïose

Since the recognition of white matter changes on computed tomography, researches were done to investigate a possible relation with ageing and cognition. This study examined whether computed tomography evidence of cerebrovascular disease in the form of white matter changes was associated with decreased implicit performance of frontal tests and with a loss of motivation in a group of 10 elderly volunteers with a mild cognitive impairment and in a group of 29 demented patients; 39 old patients (28 females: 82.4 +/- 7.1; 10 males: 75.5 +/- 11.3) cared in a psycho-geriatric day care hospital were enrolled for this essay. Motivation was evaluated with a specific scale: EAD. Patients were tested during the same period with MMSE for cognition, Cornell's scale for depression, Marin's scale for apathy. There were also assessed with a battery of frontal tests: BREF test. A brain scan was used to determinate the presence of leukoaraïosis. Table 1 give a description of the population according to the pathology. Cognitive disorder, but also apathy and loss motivation, frontal evaluation significantly differ in the two studied groups. The presence of a leukoaraïosis is associated with older people, a weaker cognitive status, a more important apathy or loss of motivation, and weaker results with frontal evaluation (table 2). Similar results were obtained considering only the frontal lesions (table 3). Age related changes of the white matter observed on computed tomography were associated with a decreased cognitive status. Leukoaraïosis is associated with loss of motivation and related with a poor results on frontal assessment. Loss of motivation is associated with certain frontal dysfunctions and with brain abnormal scan anomalies.

The Press as a Watchdog for Accounting Fraud

This paper investigates the press' role as a watchdog for accounting fraud. In choosing whether to fulfill this role, the press must trade off the benefits of providing interesting stories, and thus increasing circulation, with the costs of identifying such stories and potentially alienating business partners and advertisers. I use a sample of firms that the SEC has found guilty of committing accounting fraud to investigate how the accesses these costs and benefits. I find the press is more likely to write an article identifying accounting fraud if the firm has a high information environment (i.e. many press articles in general, high analyst following and, although weaker results, a large market value of equity). A rich information environment indicates the press can obtain information at a lower cost and that a large number of potential readers would be interested in the firm. I also find that characteristics of the fraud impact the likelihood the press will write an article. Fraud that includes material publicly misleading statements or management misappropriation of funds is more likely to trigger an article. A public statement can both attract the presses attention, thus reducing identification cost, and assure more people are interested in a follow-up to information they have used. Management misappropriation of funds, whether theft or insider trading, is likely to make a story more interesting to the public, and thus increase the benefits to the writer. I do not find the severity of the violation, based on length and number of violations noted, to influence the likelihood of an article being written. Finally, I perform a content analysis of the identified fraud articles to gain a greater understanding of how the press undertakes the watchdog role. I find that the press relies on many sources, but particularly on analysts, legal suits and auditor changes. While many types of press break the initial story, the business press provides the greatest coverage. Finally, most articles do not appear to be written by local reporters, but those that do are more likely to provide no source for information (consistent with having performed their own investigative reporting) and are less likely to rely on analysts in general. This provides some evidence of an informational difference for locally based reporters.

Prediction of chemical composition and origin identification of european sea bass ( Dicentrarchus labrax L.) by near infrared reflectance spectroscopy (NIRS)

Near infrared reflectance spectroscopy (NIRS) analysis was used to predict proximate chemical composition and identify the rearing system of 236 European sea bass caught in four Italian fish farms (extensive ponds, semi-intensive ponds, intensive tanks and intensive sea-cages). Three types of sample preparation (intact fillet portions; whole fresh minced fillet; freeze-dried minced fillet) were compared. NIRS provided good reliability in the prediction of chemical composition of sea bass fillets but weaker results in crude protein prediction. NIRS prediction of chemical composition proved to be more accurate with fresh minced fillets than intact fillet portions. The merely slight improvement of NIRS accuracy with freeze-dried samples did not justify the latter treatment, which was necessary, however, to obtain reliable information on the sea bass rearing system.

Predicting National and Regional Recessions Using Probit Modeling and Interest‐Rate Spreads

Abstract This study extends the work of Estrella and Mishkin (1996, 1998) to show that interest‐rate spreads and probit modeling can be used to predict recessions in many states as well as the nation. State recessions are defined as two or more consecutive quarters of declining real gross state product. The yield spread, SPREAD, is defined as the difference between the 10‐year Treasury bond rate and the three‐month Treasury bill rate. The national results are similar to those obtained by Estrella and Mishkin. Probit models are estimated for all 50 states using SPREAD and unemployment insurance claims, UI, as alternative explanatory variables. For 34 of the 50 states, SPREAD is significant at the 0.01 level as a predictor of state recessions. Much weaker results are obtained using UI. Simulations for the 1979–2001 period are used to compute loss functions for the national and state models at probability screens of 30, 40, 50, and 60 percent. The results demonstrate that probit models based on SPREAD can be useful in improving business and policy decisions in many states.

The Erdős–Szeméredi problem on sum set and product set

Summary The basic theme of this paper is the fact that if A is a finite set of integers, then the sum and product sets cannot both be small. A precise formulation of this fact is Conjecture 1 below due to Erd˝ os-Szemeredi (E-S). (see also (El), (T), and (K-T) for related aspects.) Only much weaker results or very special cases of this conjecture are presently known. One approach consists of assuming the sum set A + A small and then deriving that the product set AA is large (using Freiman's structure theorem) (cf. (N-T), (Na3)). We follow the reverse route and prove that if |AA| c � |A| 2 (see Theorem 1). A quantitative version of this phenomenon combined with the Plunnecke type of inequality (due to Ruzsa) permit us to settle completely a related conjecture in (E-S) on the growth in k .I f

On Macula's error-correcting pool designs

We show that Macula's claim of a Hamming distance 4 between any two candidate sets of positive clones in his pool design is incorrect. However, a previous proof of his on a weaker result (with a condition on design parameters) is correct. We also show that the condition is sharp and the distance 4 result is also sharp for arbitrary parameter values.

Zero-Inventory Conditions for a Two-Part-Type Make-to-Stock Production System

We consider the dynamic scheduling of a two-part-type make-to-stock production system using the model of Wein [12]. Exogenous demand for each part type is met from finished goods inventory; unmet demand is backordered. The control policy determines which part type, if any, to produce at each moment; complete flexibility is assumed. The objective is to minimize average holding and backorder costs. For exponentially distributed interarrival and production times, necessary and sufficient conditions are found for a zero-inventory policy to be optimal. This result indicates the economic and production conditions under which a simple make-to-order control is optimal. Weaker results are given for the case of general production times.

Remarks on excitability, stability and sign of equilibria in cooperative systems

The strict positivity of equilibria is known to be equivalent to asymptotic stability in excitable positive linear systems. In contrast with intuition, this property does not hold for nonlinear cooperative systems. However, weaker results are pointed out and proved to be effective in the analysis of several nonlinear cooperative systems.

Crown illumination limits the population growth rate of a neotropical understorey palm (Geonoma macrostachys, Arecaceae)

The importance of light as a limiting factor for growth and reproductionin tropical understorey plants is well known, but the population-levelconsequences of light limitation remain little explored. Here, I usedemographicmodelling to examine if the effect of canopy gaps on individual-levelperformance in a tropical understorey palm translates into an effect on thepopulation growth rate. The demographic effects of heterogeneity in crownillumination (index of hemispherical canopy openness), forest-phase, and othermicroenvironmental parameters were quantified using data on 2592 individuals ofall sizes in permanent plots followed over a 1.5 year period. Supplementaryexperiments investigating the effects of canopy conditions on seedlingrecruitment were also conducted. Among the microenvironmental parameters onlycrown illumination and forest-phase had strong and consistent demographiceffects. Growth and fecundity generally increased with increasing crownillumination. Under open forest-phase conditions growth tended to increase andsurvival to decrease (due to increased physical damage). Seedlings transplantedinto gap centres were damaged by solarization. The population-level effect ofheterogeneity in crown illumination and forest-phase was investigated usingtransition matrix models. The overall population growth rate was 0.999, and notsignificantly different from 1. Illumination-specific models showed thatG. macrostachys would be unable to persist at permanentlylow illumination, but would increase in density under higher illumination.Forest-phase-specific models gave similar, but weaker results. Thus, inG. macrostachys effects of canopy openness onindividual-level performance strongly limit the population growth rate. Thepresent study thereby shows that fine-scale spatiotemporal variation in canopyopenness in the tropical rain forest understorey can play a central role in thepopulation ecology of shade-tolerant understorey plants.

Impact of the variations of the mixing length in a first order turbulent closure system

This paper is devoted to the study of a turbulent circulation model. Equations are derived from the “Navier-Stokes turbulent kinetic energy” system. Some simplifications are performed but attention is focused on non linearities linked to turbulent eddy viscosity . The mixing length acts as a parameter which controls the turbulent part in . The main theoretical results that we have obtained concern the uniqueness of the solution for bounded eddy viscosities and small values of and its asymptotic decreasing as in more general cases. Numerical experiments illustrate but also allow to extend these theoretical results: uniqueness is proved only for small enough while regular solutions are numerically obtained for any values of . A convergence theorem is proved for turbulent kinetic energy: as but for velocity we obtain only weaker results. Numerical results allow to conjecture that and as So we can conjecture that this classical turbulent model obtained with one degree of closure regularizes the solution.