Miracle-dz/UniFAR-FTUs huggingface dataset:
Electrochemical Identification of Higher Oxides of Manganese in Corrosion Relevant Deposits Formed by Microorganisms

Certain cases of microbiologically influenced corrosion (MIC) in natural waters are attributed to the activity of manganese oxidizing microorganisms (MOMOs). These cases are typically related to stainless steel and are characterized by an anodic potential shift of the steel. This so-called ennoblement is attributed to microbiologically formed deposits containing manganese dioxide and related Mn(III,IV)-compounds. A method for the identification of such oxidizing compounds in the complex matrices of natural samples, often mixed with corrosion products, by directly assessing their electrochemical properties seems of interest. Cyclic voltammetry with carbon paste electrodes with electrolytic binder in an alkaline medium was evaluated for this purpose. The results obtained with samples from 5 different locations and of laboratory cultures are presented. Samples of typically less than 1 mg are required and semiquantitative information is received from the cathodic current peak during the reduction cycle. A subsequent anodic cycle provides redundant information due to reoxidation and aids in the interpretation of the voltammograms. The method may be considered as an additional electrochemical tool for the characterization of deposits in cases of MIC by MOMOs.
Differential Evolutionary Fate of an Ancestral Primate Endogenous Retrovirus Envelope Gene, the EnvV Syncytin, Captured for a Function in Placentation

Syncytins are envelope genes of retroviral origin that have been co-opted for a role in placentation. They promote cell–cell fusion and are involved in the formation of a syncytium layer—the syncytiotrophoblast—at the materno-fetal interface. They were captured independently in eutherian mammals, and knockout mice demonstrated that they are absolutely required for placenta formation and embryo survival. Here we provide evidence that these “necessary” genes acquired “by chance” have a definite lifetime with diverse fates depending on the animal lineage, being both gained and lost in the course of evolution. Analysis of a retroviral envelope gene, the envV gene, present in primate genomes and belonging to the endogenous retrovirus type V (ERV-V) provirus, shows that this captured gene, which entered the primate lineage >45 million years ago, behaves as a syncytin in Old World monkeys, but lost its canonical fusogenic activity in other primate lineages, including humans. In the Old World monkeys, we show—by in situ analyses and ex vivo assays—that envV is both specifically expressed at the level of the placental syncytiotrophoblast and fusogenic, and that it further displays signs of purifying selection based on analysis of non-synonymous to synonymous substitution rates. We further show that purifying selection still operates in the primate lineages where the gene is no longer fusogenic, indicating that degeneracy of this ancestral syncytin is a slow, lineage-dependent, and multi-step process, in which the fusogenic activity would be the first canonical property of this retroviral envelope gene to be lost.
Latitudinal Diversity of Sea Anemones (Cnidaria: Actiniaria)

We sought to determine if the global distribution of sea anemones (cnidarian order Actiniaria) conforms to the classic pattern of biogeography—taxon richness at the equator with attenuation toward the poles—a pattern that is derived almost entirely from data on terrestrial plants and animals. We plotted the empirical distribution of species occurrences in 10° bands of latitude based on published information, then, using the Chao2 statistic, inferred the completeness of that inventory. We found the greatest species richness of sea anemones at 30–40° N and S, with lower numbers at tropical latitudes and the fewest species in polar areas. The Chao2 statistic allowed us to infer that the richness pattern we found is not due to particularly poor knowledge of tropical sea anemones. No 10° band of latitude has less than 60% of the theoretical number of species known, but for only about half of them could we reject the null hypothesis (P = 0.05) that information is complete; anemone diversity is best documented at high latitudes. We infer that the 1089 valid species currently known constitute about 70% of the theoretical total of about 1500 species of Actiniaria. The distribution pattern of sea anemone species resembles that of planktonic foraminiferans and benthic marine algae, although planktonic bacteria, marine bivalves, and shallow and deep scleractinian corals show the terrestrial pattern of equatorial richness attenuating with latitude. Sea anemone species richness is complementary to that of scleractinian corals at many scales; our findings affirm it at the global scale.
On the Stability and Optimal Decentralized Throughput of CSMA with Multipacket Reception Capability ∗

With the improvement of the physical layer’s ability to receive multiple packets sent simultaneously, the classical collision channel model no longer applies and a general MPR model should be employed. We investigate the effect of MPR on the CSMA protocol, which previously have not been studied under such model. By analyzing the stability region of CSMA, we find that CSMA’s open-loop throughput is the same as that of S-ALOHA when signal propagation delay is considered. Then we derive the optimal decentralized closed-loop throughput of CSMA and conclude that carrier sensing can provide throughput gain over S-ALOHA but only if the MPR capability is not sufficiently strong. Essentially carrier sensing can be interpreted as an enhancement over optimal scheduling, both of which become unnecessary for strong physical layers.
Reciprocal inhibition of voltage-gated potassium currents (IK(V)) by activation of cannabinoid CB1 and dopamine D1 receptors in ON bipolar cells of goldfish retina

Cannabinoid CB1 receptor (via Gs) and dopamine D2 receptor (via Gi/o) antagonistically modulate goldfish cone membrane currents. As ON bipolar cells have CB1 and D1 receptors, but not D2 receptors, we focused on whether CB1 receptor agonist and dopamine interact to modulate voltage-dependent outward membrane K+ currents IK(V) of the ON mixed rod/cone (Mb) bipolar cells. Whole-cell currents were recorded from Mb bipolar cells in goldfish retinal slices. Mb bipolar cells were identified by intracellular filling with Lucifer yellow. The bath solution was calcium-free and contained 1 mM cobalt to block indirect calcium-dependent effects. Dopamine (10 μM) consistently increased IK(V) by a factor of 1.57 ± 0.12 (S.E.M., n = 15). A CB receptor agonist, WIN 55212-2 (0.25–1 μM), had no effect, but 4 μM WIN 55212-2 suppressed IK(V) by 60%. If IK(V) was first increased by 10 μM dopamine, application of WIN 55212-2 (0.25–1 μM) reversibly blocked the effect of dopamine even though these concentrations of WIN 55212-2 had no effect of their own. If WIN 55212-2 was applied first and dopamine (10 μM) was added to the WIN-containing solution, 0.1 μM WIN 55212-2 blocked the effect of dopamine. All effects of WIN 55212-2 were blocked by coapplication of SR 141716A (CB1 antagonist) and pretreatment with pertussis toxin (blocker of Gi/o) indicating action via CB1 receptor activation of G protein Gi/o. Coactivation of CB1 and D1 receptors on Mb bipolar cells produces reciprocal effects on IK(V). The CB1-evoked suppression of IK(V) is mediated by G protein Gi/o, whereas the D1-evoked enhancement is mediated by G protein Gs. As dopamine is a retinal “light” signal, these data support our notion that endocannabinoids function as a “dark” signal, interacting with dopamine to set retinal sensitivity.
Neurokinin-1 Receptor Expression and Its Potential Effects on Tumor Growth in Human Pancreatic Cancer

The neurokinin-1 receptor (NK-1R) and its ligand substance P (SP) are involved in the pathogenesis of certain neural tumors. Because nerves are significantly altered in pancreatic cancer, evidence for alteration of this pathway in human pancreatic cancer was sought. Expression of NK-1R was analyzed by real-time quantitative RT-PCR, in situ hybridization, immunohistochemistry, and Western blot analysis in normal human pancreatic and pancreatic cancer tissue samples and in pancreatic cancer cell lines. Furthermore, the influence of SP analogs and of the NK-1R antagonist MEN 11467 on pancreatic cancer cell growth was analyzed by sulforhodamine B (SRB) assay. By real-time quantitative RT-PCR, NK-1R mRNA was increased 36.7-fold (p < 0.001) in human pancreatic cancer samples compared with normal controls. Enhanced NK-1R expression levels were not related to tumor grade but were associated with advanced tumor stage and poorer prognosis. By in situ hybridization and immunohistochemistry, NK-1R mRNA and immunoreactivity were only occasionally weakly present in acinar and ductal cells in the normal pancreas. In contrast, moderate to strong NK-1R mRNA signals and immunoreactivity were present in most cancer cells. By Western blot analysis, NK-1R was increased 26-fold (p < 0.01) in pancreatic cancer samples in comparison to normal controls. NK-1R mRNA was detected in five pancreatic cancer cell lines by real-time quantitative RT-PCR, with the highest levels in CAPAN-1 cells and the lowest in ASPC-1 cells. SP analogs stimulated pancreatic cancer cell growth, depending on the NK-1R expression level, and this effect could be blocked by a selective NK-1R antagonist. These findings illustrate that the NK-1R pathway is activated in human pancreatic cancer and has the potential to contribute to cancer cell growth, thus suggesting the existence of a neuro-cancer cell interaction in vivo.
An Analysis Comparison of Reliability Mechanisms for Improving Reliable Mobile Multicast Protocols

Existing reliable multicast protocols are designed to perform well in wired networking environments. However, in mobile networking environments, these reliable mobile multicast protocols are not optimal as they do not take into account the limitations of power (energy), storage capacity, processing power, impairments of wireless communication channels, and the frequent changes of location and the resulting loss of network connectivity. This paper analyses four hybrid reliable multicast schemes, namely NAK-based schemes, ACK-based schemes, ACK-based schemes with FEC (Forward Error Correction), and NAK-based schemes with FEC that are suitable for mobile networking environments and quantifies their performance. These four schemes differ from the generic sender-initiated and receiver-initiated reliable multicast protocols in that they rely on a mixture of multicasting and unicasting for providing reliability. This analysis is used to show that NAK-based schemes with FEC is best suited for reliable multicasting in mobile environments as they provide excellent performance in terms of average wireless channel utilization and average processing time, independently of the number of MHs.
Regional cerebral blood flow throughout the sleep-wake cycle. An H2(15)O PET study.

To assess dynamic changes in brain function throughout the sleep-wake cycle, CBF was measured with H2(15)O and PET in 37 normal male volunteers: (i) while awake prior to sleep onset; (ii) during Stage 3-4 sleep, i.e. slow wave sleep (SWS); (iii) during rapid eye movement (REM) sleep; and (iv) upon waking following recovery sleep. Subjects were monitored polysomnographically and PET images were acquired throughout the course of a single night. Stage-specific contrasts were performed using statistical parametric mapping. Data were analysed in repeated measures fashion, examining within-subject differences between stages [pre-sleep wakefulness-SWS (n = 20 subjects); SWS-post-sleep wakefulness (n = 14); SWS-REM sleep (n = 7); pre-sleep wakefulness-REM sleep (n = 8); REM sleep-post-sleep wakefulness (n = 7); pre-sleep wakefulness-post-sleep wakefulness (n = 20)]. State dependent changes in the activity of centrencephalic regions, including the brainstem, thalamus and basal forebrain (profound deactivations during SWS and reactivations during REM sleep) are consistent with the idea that these areas are constituents of brain systems which mediate arousal. Shifts in the level of activity of the striatum suggested that the basal ganglia might be more integrally involved in the orchestration of the sleep-wake cycle than previously thought. State-dependent changes in the activity of limbic and paralimbic areas, including the insula, cingulate and mesial temporal cortices, paralleled those observed in centrencephalic structures during both REM sleep and SWS. A functional dissociation between activity in higher order, heteromodal association cortices in the frontal and parietal lobes and unimodal sensory areas of the occipital and temporal lobes appeared to be characteristic of both SWS and REM sleep. SWS was associated with selective deactivation of the heteromodal association areas, while activity in primary and secondary sensory cortices was preserved. SWS may not, as previously thought, represent a generalized decrease in neuronal activity. On the other hand, REM sleep was characterized by selective activation of certain post-rolandic sensory cortices, while activity in the frontoparietal association cortices remained depressed. REM sleep may be characterized by activation of widespread areas of the brain, including the centrencephalic, paralimbic and unimodal sensory regions, with the specific exclusion of areas which normally participate in the highest order analysis and integration of neural information. Deactivation of the heteromodal association areas (the orbital, dorsolateral prefrontal and inferior parietal cortices) constitutes the single feature common to both non-REM and REM sleep states, and may be a defining characteristic of sleep itself. The stages of sleep could also be distinguished by characteristic differences in the relationships between the basal ganglia, thalamic nuclei and neocortical regions of interest.
Comprehending Object and Process Models: An Empirical Study

We report the results of an empirical study comparing user comprehension of object oriented (OO) and process oriented (PO) models. The fundamental difference is that while OO models tend to focus on structure, PO models tend to emphasize behaviour or processes. Proponents of the OO modeling approach argue that it lends itself naturally to the way humans think. However, evidence from research in cognitive psychology and human factors suggests that human problem solving is innately procedural. Given these conflicting viewpoints, we investigate empirically if OO models are in fact easier to understand than PO models. But, as suggested by the theory of cognitive fit, model comprehension may be influenced by task-specific characteristics. We therefore compare OO and PO models based on whether the comprehension activity involves: 1) only structural aspects, 2) only behavioral aspects, or 3) a combination of structural and behavioral aspects. We measure comprehension through subjects' responses to questions designed along these three dimensions. Results show that for most of the simple questions, no significant difference was observed insofar as model comprehension is concerned. For most of the complex questions, however, the PO model was found to be easier to understand than the OO model. In addition to describing the process and the outcomes of the experiments, we present the experimental method employed as a viable approach for conducting research into various phenomena related to the efficacy of alternative systems analysis and design methods. We also identify areas where future research is necessary, along with a recommendation of appropriate research methods for empirical examination.
Diabetes mellitus concomitantly facilitates the induction of long‐term depression and inhibits that of long‐term potentiation in hippocampus

Memory impairments, which occur regularly across species as a result of ageing, disease (such as diabetes mellitus) and psychological insults, constitute a useful area for investigating the neurobiological basis of learning and memory. Previous studies in rats found that induction of diabetes (with streptozotocin, STZ) impairs long‐term potentiation (LTP) but enhances long‐term depression (LTD) induced by high‐ (HFS) and low‐frequency stimulations (LFS), respectively. Using a pairing protocol under whole‐cell recording conditions to induce synaptic plasticity at Schaffer collateral synapses in hippocampal CA1 slices, we show that LTD and LTP have similar magnitudes in diabetic and age‐matched control rats. But, in diabetic animals, LTD is induced at more polarized and LTP more depolarized membrane potentials (Vms) compared with controls: diabetes produces a 10 mV leftward shift in the threshold for LTD induction and 10 mV rightward shift in the LTD–LTP crossover point of the voltage–response curve for synaptic plasticity. Prior repeated short‐term potentiations or LTP are known to similarly, though reversibly, lower the threshold for LTD induction and raise that for LTP induction. Thus, diabetes‐ and activity‐dependent modulation of synaptic plasticity (referred to as metaplasticity) display similar phenomenologies. In addition, compared with naïve synapses, prior induction of LTP produces a 10 mV leftward shift in Vms for inducing subsequent LTD in control but not in diabetic rats. This could indicate that diabetes acts on synaptic plasticity through mechanisms involved in metaplasticity. Persistent facilitation of LTD and inhibition of LTP may contribute to learning and memory impairments associated with diabetes mellitus.
Determination of the Loading Rate Needed to Obtain Environmentally Assisted Cracking in Rising Load Tests

A method is proposed to calculate the loading rate needed to induce environmentally assisted cracking (EAC) in precracked specimens tested under rising load. The procedure applies to materials that fracture by ductile tearing under inert conditions and requires some EAC data, although these may be obtained from one of several sources. A fundamental basis is provided to explain why the rising load test can serve as an accelerated test. Application to a medium strength steel in synthetic seawater and a pipeline steel in a carbonate/bicarbonate solution shows good results: EAC was exhibited and a close estimate of the threshold stress intensity factor for sustained load was obtained in less than one tenth the time required by conventional methods.
Targeting multiple pathways in gliomas with stem cell and viral delivered S-TRAIL and Temozolomide

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively kills tumor cells. However, its short half-life, poor delivery, and TRAIL-resistant tumor cells have diminished its clinical efficacy. In this study, we explored whether novel delivery methods will represent new and effective ways to treat gliomas and if adjuvant therapy with the chemotherapeutic agent temozolomide would enhance the cytotoxic properties of TRAIL in glioma lines resistant to TRAIL monotherapy. We have engineered adeno-associated virus (AAV) vectors encoding recombinant secreted TRAIL (S-TRAIL) and bioluminescent-fluorescent marker fusion proteins and show that AAV-delivered S-TRAIL leads to varying degrees of killing in multiple glioma lines, which correspond with caspase-3/7 activation. In vivo, dual bioluminescent imaging revealed efficient delivery of therapeutic AAV vectors directly into the tumor mass, which induced marked attenuation of tumor progression. Treatment of glioma cells with the chemotherapeutic agent temozolomide alone lead to a significant accumulation of cells in G2-M phase, activated the cell cycle checkpoint protein Chk1, and increased death receptor expression in a time-dependent manner. Furthermore, combined treatment with AAV-S-TRAIL or neural stem cell-S-TRAIL and temozolomide induced cell killing and markedly up-regulated proapoptotic proteins in glioma cells least sensitive to TRAIL. This study elucidates novel means of delivering S-TRAIL to gliomas and suggests combination of clinically relevant temozolomide and S-TRAIL may represent a new therapeutic option with increased potency for glioblastoma patients. [Mol Cancer Ther 2008;7(11):3575–85]
Good Clinical Teachers Likely to be Specialist Role Models: Results from a Multicenter Cross-Sectional Survey

Context Medical educational reform includes enhancing role modelling of clinical teachers. This requires faculty being aware of their role model status and performance. We developed the System for Evaluation of Teaching Qualities (SETQ) to generate individualized feedback on previously defined teaching qualities and role model status for faculty in (non) academic hospitals. Objectives (i) To examine whether teaching qualities of faculty were associated with their being seen as a specialist role model by residents, and (ii) to investigate whether those associations differed across residency years and specialties. Methods & Materials Cross-sectional questionnaire survey amongst 549 Residents of 36 teaching programs in 15 hospitals in the Netherlands. The main outcome measure was faculty being seen as specialist role models by residents. Statistical analyses included (i) Pearson's correlation coefficients and (ii) multivariable logistic generalized estimating equations to assess the (adjusted) associations between each of five teaching qualities and ‘being seen as a role model’. Results 407 residents completed a total of 4123 evaluations of 662 faculty. All teaching qualities were positively correlated with ‘being seen as a role model’ with correlation coefficients ranging from 0.49 for ‘evaluation of residents’ to 0.64 for ‘learning climate’ (P<0.001). Faculty most likely to be seen as good role models were those rated highly on ‘feedback’ (odds ratio 2.91, 95% CI: 2.41–3.51), ‘a professional attitude towards residents’ (OR 2.70, 95% CI: 2.34–3.10) and ‘creating a positive learning climate’ (OR 2.45, 95% CI: 1.97–3.04). Results did not seem to vary much across residency years. The relative strength of associations between teaching qualities and being seen as a role model were more distinct when comparing specialties. Conclusions Good clinical educators are more likely to be seen as specialist role models for most residents.
Plagiarism - A Survey

Plagiarism in the sense of "theft of intellectual property" has been around for as long as humans have produced work of art and research. However, easy access to the Web, large databases, and telecommunication in general, has turned plagiarism into a serious problem for publishers, researchers and educational institutions. In this paper, we concentrate on textual plagiarism (as opposed to plagiarism in music, paintings, pictures, maps, technical drawings, etc.). We first discuss the complex general setting, then report on some results of plagiarism detection software and finally draw attention to the fact that any serious investigation in plagiarism turns up rather unexpected side-effects. We believe that this paper is of value to all researchers, educators and students and should be considered as seminal work that hopefully will encourage many still deeper investigations.