Miracle-dz/UniFAR-FTUs huggingface dataset:
Sperm chemotaxis is driven by the slope of the chemoattractant concentration field

Spermatozoa of marine invertebrates are attracted to their conspecific female gamete by diffusive molecules, called chemoattractants, released from the egg investments in a process known as chemotaxis. The information from the egg chemoattractant concentration field is decoded into intracellular Ca2+ concentration ([Ca2+]i) changes that regulate the internal motors that shape the flagellum as it beats. By studying sea urchin species-specific differences in sperm chemoattractant-receptor characteristics we show that receptor density constrains the steepness of the chemoattractant concentration gradient detectable by spermatozoa. Through analyzing different chemoattractant gradient forms, we demonstrate for the first time that Strongylocentrotus purpuratus sperm are chemotactic and this response is consistent with frequency entrainment of two coupled physiological oscillators: i) the stimulus function and ii) the [Ca2+]i changes. We demonstrate that the slope of the chemoattractant gradients provides the coupling force between both oscillators, arising as a fundamental requirement for sperm chemotaxis.
Hybrid-empirical neural model for indoor/outdoor path loss calculation

Accurate prediction the coverage area provided by a given transmitting station is crucial to the efficient design of wireless communication systems. This paper presents hybrid-empirical neural model for indoor/outdoor loss calculation as alternative method to previous propagation models. Its primary advantage is the consideration many global and local parameters influencing the EM propagation. Further, it has great simulation speed that can give good base for introducing it in applications which simulation has to be finished in certain period of time.
Fitness Costs and Stability of a High-Level Ciprofloxacin Resistance Phenotype in Salmonella enterica Serotype Enteritidis: Reduced Infectivity Associated with Decreased Expression of Salmonella Pathogenicity Island 1 Genes

ABSTRACT The fitness costs associated with high-level fluoroquinolone resistance were examined for phenotypically and genotypically characterized ciprofloxacin-resistant Salmonella enterica serotype Enteritidis mutants (104-cip and 5408-cip; MIC, >32 μg/ml). The stability of the fluoroquinolone resistance phenotype in both mutants was investigated to assess whether clones with better fitness could emerge in the absence of antibiotic selective pressure. Mutants 104-cip and 5408-cip displayed altered morphology on agar and by electron microscopy, reduced growth rates, motility and invasiveness in Caco-2 cells, and increased sensitivity to environmental stresses. Microarray data revealed decreased expression of virulence and motility genes in both mutants. Two clones, 104-revert and 1A-revertC2, with ciprofloxacin MICs of 3 and 2 μg/ml, respectively, were recovered from separate lineages of 104-cip after 20 and 70 passages, respectively, on antibiotic-free agar. All fitness costs, except motility, were reversed in 104-revert. Potential mechanisms associated with reversal of the resistance phenotype were examined. Compared to 104-cip, both 104-revert and 1A-revertC2 showed decreased expression of acrB and soxS but still overexpressed marA. Both acquired additional mutations in SoxR and ParC, and 1A-revertC2 acquired two mutations in MarA. The altered porin and lipopolysaccharide (LPS) profiles observed in 104-cip were reversed. In contrast, 5408-cip showed no reversal in fitness costs and maintained its high-level ciprofloxacin resistance for 200 passages on antibiotic-free agar. In conclusion, high-level ciprofloxacin resistance in S. Enteritidis is associated with fitness costs. In the absence of antibiotic selection pressure, isolates may acquire mutations enabling reversion to an intermediate-level ciprofloxacin resistance phenotype associated with less significant fitness costs.
“I would rather die”: reasons given by 16-year-olds for not continuing their study of mathematics

Improving participation rates in specialist mathematics after the subject ceases to be compulsory at age 16 is part of government policy in England. This article provides independent and recent support for earlier findings concerning reasons for non-participation, based on free response and closed items in a questionnaire with a sample of over 1500 students in 17 schools, close to the moment of choice. The analysis supports findings that perceived difficulty and lack of confidence are important reasons for students not continuing with mathematics, and that perceived dislike and boredom, and lack of relevance, are also factors. There is a close relationship between reasons for non-participation and predicted grade, and a weaker relation to gender. An analysis of the effects of schools, demonstrates that enjoyment is the main factor differentiating schools with high and low participation indices. Building on discussion of these findings, ways of improving participation are briefly suggested.
Estimated background doses of [67Ga]-DTPA-USPIO in normal Balb/c mice as a potential therapeutic agent for liver and spleen cancers

IntroductionThe aim of this study was to evaluate the biodistribution of dextran-coated iron oxide nanoparticles labeled with gallium-67 (67Ga) in various organs by intravenous injection in Balb/c mice. MethodsUltrasmall superparamagnetic iron oxide (USPIO) was successively labeled with 67Ga-chloride after chelation with freshly prepared cyclic DTPA-dianhydride. The labeling efficiency of USPIOs labeled with 67Ga is above 98%. Sixty-five mice were killed at 13 different time points. The percentage of injected dose per gram of each organ was measured by direct counting for 19 harvested organs of the mice. The medical internal radiation dose formula was applied to extrapolate data from mouse to human and to predict the absorbed radiation dose for various organs in the human body. ResultsThe biodistribution of 67Ga-USPIO in Balb/c mice showed that 75% of the injected dose accumulated in the spleen and liver 15 min after injection. These nanoparticles remained in the liver for more than 7 days after injection, whereas their clearance was very fast from other organs. Extrapolating these data to the intravenous injection of 67Ga-USPIO in humans gave an estimated absorbed dose of 36.38 mSv/MBq for the total body, and the highest effective absorbed dose was seen in the liver (32.9 mSv/MBq). ConclusionHigh uptakes of USPIO nanoparticles in the liver and spleen and their fast clearance from other tissues suggest that these nanoparticles labeled with a &bgr;-emitter radioisotope could be suitable as treatment agents for spleen and liver malignancies only if the organ tolerance dose is not exceeded.
Posttranscriptional effect of insulin-like growth factor-I on interleukin-1beta-induced type II-secreted phospholipase A2 gene expression in rabbit articular chondrocytes.

Large amounts of type II-secreted phospholipase A2 (type II sPLA2) are secreted into inflammatory synovial fluid and they are believed to induce the synthesis of lipid mediators by articular chondrocytes. Preliminary experiments showed that insulin-like growth factor-I, which counteracts cartilage degradation in arthritis, inhibits interleukin-1beta-induced type II sPLA2 gene expression in rabbit articular chondrocytes (Berenbaum, F., G. Thomas, S. Poiraudeau, G. Bereziat, M.T. Corvol, and J. Masliah. 1994. FEBS Lett. 340: 51-55). The present study showed that IL-1beta induced the sustained synthesis of prostaglandin E2 and a parallel increase in type II sPLA2 gene expression (assessed by enzymatic activity and Northern blot analysis), but no increase in cytosolic PLA2 gene expression (assessed by Northern and Western blot analysis) or cytosolic PLA2 activity in rabbit articular chondrocytes. IGF-I inhibited both IL-1beta-stimulated PGE2 synthesis and type II sPLA2 gene expression, but had no effect on cytosolic PLA2 gene expression. Nuclear run-on experiments revealed that IL-1beta stimulated the transcription rate of type II sPLA2 gene, giving rise to long-lived mRNA in cells treated with actinomycin D. IGF-I did not affect transcription rate, suggesting that it acts as a post-transcriptional step. Sucrose density gradient analysis of the translation step showed no effect of IGF-I on the entry of type II sPLA2 mRNA into the polysomal pool or on its distribution into the various polysomal complexes, suggesting that IGF-I does not act on the translation of the mRNA. Lastly, IGF-I strongly decreased the half-life of IL-1beta-induced type II sPLA2 mRNA (from 92 to 12 h), suggesting that IGF-I destabilizes mRNA. These data demonstrate that IL-1beta stimulates the transcription rate of the type II sPLA2 gene and gives rise to a very stable mRNA. In contrast, IGF-I decreases the half-life of the type II sPLA2 message.
Advances in Economics and Econometrics: Identification of Nonadditive Structural Functions

© Cambridge University Press 2007.INTRODUCTION When latent variates appear nonadditively in a structural function the effect of a ceteris paribus change in an observable argument of the function can vary across people measured as identical. Models that admit nonadditive structural functions permit responses to policy interventions to have probability distributions. Knowledge of the distributions of responses is important for welfare analysis and it is good to know what conditions secure identification of these distributions. This lecture examines some aspects of this problem. Early studies of identification in econometrics dealt almost exclusively with linear additive “error” models. The subsequent study of identification in nonlinear models was heavily focused on additive error models until quite recently and only within the last ten years has there has been extensive study of identification in nonadditive error models. This lecture examines some of these recent results, concentrating on models which admit no more sources of stochastic variation than there are observable stochastic outcomes. Models with this property are interesting because they are direct generalizations of additive error models and of the classical linear simultaneous equation models associated with the work of the Cowles Commission, and because the addition of relatively weak nonparametric restrictions results in models which identify complete structural functions or specific local features of them. Nonparametric restrictions are interesting because they are consonant with the information content of economic theory. Even if parametric or semiparametric restrictions are imposed when estimation and inference are done, it is good to know nonparametric identification conditions because they tell us what core elements of the model are essential for identification and which are in principle falsifiable.
Cerebro–fronto–facial syndrome (Dandy‐Walker Variant and Frontofacial Dysmorphisms): report of the first case identified by increased nuchal translucency beyond 13+6 weeks

ABSTRACT A 32‐year‐old gravida 2, para 1 woman, with a previous uneventful pregnancy, underwent first trimester ultrasound screening for Down syndrome at 13 weeks according to the Fetal Medicine Foundation guidelines (http://www.fetalmedicine.com/pdf/11‐14/english/FMF‐English.pdf). The ultrasound showed increased nuchal translucency (NT) of 8.9 mm with an estimated risk of Down syndrome of 1:8. Fetal karyotype was normal 46,XX by chorionic villus sampling. The patient underwent weekly ultrasound and at 19 weeks of gestation, a dilatation of the 4th ventricle with partial agenesis of the cerebellar vermis and normal posterior fossa were observed by transvaginal transcerebellar section of the fetal head. This finding was consistent with a diagnosis of Dandy‐Walker variant and the patient opted for termination of pregnancy after extensive counselling. Autoptic examination confirmed the prenatal ultrasonographic findings and revealed signs of an underlying cerebro–fronto–facial syndrome due to the presence of facial dysmorphisms consistent with horizontal eyelid, high nasal root, low set ears and a wide forehead. Increased NT is not only a common phenotypic expression of chromosomal abnormalities, but is also associated with a wide range of fetal defects and genetic syndromes. Careful ultrasonographic follow‐up is mandatory in all cases of increased first trimester nuchal translucency with normal karyotype in order to identify associated anomalies.
Hippocampal atrophy, whole brain volume, and white matter lesions in older hypertensive subjects

Objective: To determine the potential role of whole brain atrophy, hippocampal atrophy, or both, and small vessel disease/white matter lesions as mechanisms underlying the cognitive impairment associated with hypertension. Methods: Using MRI scanning the authors determined hippocampal volumes, whole brain volumes, and location and severity of white matter lesions, using Scheltens scale, in 103 hypertensive (166 ± 8/88 ± 7 mm Hg, 54 female) and 51 normotensive (132 ± 12/74 ± 7 mm Hg, 21 female) subjects age ≥ 70 years. Results: Compared to normotensive subjects, older hypertensive subjects had significantly smaller whole brain volumes (887 ± 109 vs 930 ± 97 cm3, p = 0.02) and nonsignificantly reduced hippocampal volumes (5.39 ± 1.60 vs 5.67 ± 1.80 cm3, p = 0.33). Hypertensive subjects had an increased burden of periventricular lesions: bands (p = 0.03), frontal caps (p = 0.08), occipital caps (p = 0.07), and total periventricular hyperintensities (p = 0.02). They also had higher scores in subcortical areas: frontal (p = 0.04), temporal (p = 0.03), and deep white matter areas (p = 0.05). A correlation was found between whole brain volumes and systolic blood pressure (r = −0.19, p = 0.02). No correlation was seen between whole brain volumes and white matter lesion burden. Conclusions: Moderate hypertension in non-impaired older subjects is associated with smaller whole brain volume and an increased burden of subcortical and periventricular white matter lesions.
Pax‐7 Immunoreactivity in the Post‐natal Chicken Central Nervous System

In this immunocytochemical study on the constitutive expression of Pax‐7 protein in the postnatal chicken brain, Pax‐7 showed region and cell type specific expression. In the optic tectum, only cells in grey matter showed positive immunoreactivities (IRs), whereas those in the white matters did not show any IRs. In thalamic nuclei and several pontine nuclei, we also localized Pax‐7 positive IRs. On the contrary, in the cerebellum, Pax‐7 was mainly localized within the Bergmann glia, whereas Purkinje cells did not show any IRs. In double immunolabelling studies, most of the Pax‐7 IRs did not originate from neuroglial cells such as oligodendrocytes, microglia or astrocytes, but from neurons, with the exception of Bergmann glia in the cerebellum. The presence of Pax‐7 IRs in the adult chicken brain could suggest that Pax‐7 might play a role in maintaining normal physiological function in some postnatal chicken brain cells.
How Federal Reserve Discussions Respond to Increased Transparency

We analyze how the behavior of the Federal Open Market Committee changed after the statutory enforcement of transparency laws in 1993. To do this, we develop techniques to describe how language use changes over time. For a set of widely used vector space metrics, we demonstrate how to decompose aggregate changes into each individual dimension's contribution (such as a particular word's influence). Our approach can be generalized to account for associations between document dimensions (such as word definitions or meanings). Using various documents released by the Federal Reserve from 1976-2007, covering both years in which the FOMC knew its deliberations would eventually be made public, and years in which it believed no records were kept, we find that FOMC deliberations became more similar to the always-public press releases in the transparency regime. FOMC members shifted their comments towards popular economic subjects, such as "inflation" and "growth," and away from personal opinions, like "think. " In this setting, the observed changes are not purely substitution across words with the same meaning, as the results are robust to accounting for semantic relations.
Finite Element Modeling of Electric Field Effects of TASER Devices on Nerve and Muscle

TASERs deliver electrical pulses that can temporarily incapacitate subjects. The goal of this paper is to analyze the distribution of currents in muscle layers and understand the electro-muscular incapacitation safety and efficacy of TASERs. The analyses describe skeletal muscle and motor nerve activation, cell electroporation and current and electric field distributions through skin, fat and muscle layers, under worst-case assumptions for TASER electrode penetration and separation. For the muscle layer, the analysis predicts worst-case current-density and field-strength values of 94 mA/cm2 and 47 V/cm. Both values are higher than thresholds required for neuromuscular activation but significantly lower than levels needed for permanent cellular electroporation or tissue damage. The results indicate that TASERs are safe and effective in producing temporary subject incapacitation
Are UK Financial Markets SAD? A Behavioural Finance Analysis

Behavioural finance argues that some market anomalies can be explained by assuming investors are not always fully rational. This thesis contributes a greater understanding of the relationship between investor mood and financial markets, through exploring the effect of seasonal affective disorder (SAD) on UK financial markets . Chapter 2, the first empirical chapter, investigates the SAD effect on UK stock portfolio returns, by employing daily returns of all stocks traded on the London Stock Exchange (LSE) from 1988 to 2011. The chapter constructs SAD variables and six stock portfolios to examine the SAD effect in different stock portfolios, with some well-known market anomalies and weather factors are considered. The estimation result supports the existence of the SAD effect in UK stock portfolio returns, and the SAD effect is more pronounced in small size stock portfolios. Chapter 3, explores the SAD effect on UK stock trading activities, by applying a variety of econometric techniques to ascertain whether SAD affects stock portfolio turnover. The analysis indicates the more people suffer from SAD, the less stock turnover, and the SAD effect is more influential on small size stock turnover. Chapter 4 turns to bond markets, aiming to ascertain the SAD effect on UK government bond returns. We study the relationship between SAD indicators and eight government bond returns, and a positive correlation between SAD indicators and government bond returns are uncovered. The result suggests that investors prefer investing in government bonds when suffering from SAD. Overall, this thesis demonstrates a clear and significant relationship between investor mood and UK financial markets, through exploring the SAD effect on stock and government bond markets. This thesis concludes that the onset of SAD leads to lower stock returns and turnover, and higher government bond returns; and that recovery from SAD leads to higher stock returns and turnover, and lower government bond returns.
Variability of mammary blood flow in lactating Holstein-Friesian cows during the first twelve weeks of lactation.

The goals of the present study were to measure mammary blood flow volume (BFV) during the first 12 wk of lactation in dairy cows by using color Doppler sonography and to determine what affects the mammary blood flow. Forty cows were examined via color Doppler sonography on d 1, 7, 14, 28, 56, and 84 after parturition (d 0). The total BFV (BFV(total)) to the 4 mammary glands was calculated by measuring time-averaged maximum velocities (TAMV) and cross-sectional areas (A) of the left and right pudendoepigastric trunks via transrectal color Doppler sonography. Because there were no significant differences in A, TAMV, and BFV between the right and left pudendoepigastric trunks, the means of A and TAMV, and the BFV(total) of both trunks were used for calculations. The intraindividual and interindividual variability of repeated BFV measures quantified by intraclass correlation coefficients were 96 and 98%, respectively. The BFV(total) ranged from 19.9 to 27.9 L/min, with a mean of 22.3+/-4.9 L/min. Interindividual differences in BFV values were attributable to variations in A and TAMV. The interindividual variability of the BFV(total), which was determined using the coefficients of variation of the BFV(total) on individual days, ranged from 16 to 28%. All the cows had similar changes in the BFV(total) during the study. Changes in BFV(total) were not correlated with changes in the mean of A, but there was a good correlation between changes in BFV(total) and in the mean of TAMV (r=0.94). The BFV(total) was highest on d 1 of lactation, decreased 28% by d 7, and remained at this level until d 28. By d 56, the BFV(total) had increased by 15% compared with d 14 and by 10% compared with d 28. The BFV(total) on d 84 was significantly different from all other days except d 56. There were moderate correlations between daily milk yield and BFV on individual days (0.24
Predictors of time spent outdoors among children: 5-year longitudinal findings

Background Given the importance of physical activity for health and age-related declines in physical activity, understanding influences on related behaviours, such as time outdoors, is crucial. This study aimed to understand individual, social and physical environmental influences on longitudinal changes in urban children's time outdoors. Methods The time children spent outdoors in 2001, 2004 and 2006 (aged 5–6 and 10–12 years at baseline) was reported by their parents (n=421). In 2001, individual, social and physical environmental factors were self-reported by parents. Generalized estimating equations examined longitudinal relationships between baseline predictors and average change in time outdoors over 5 years. Results Children's time outdoors significantly declined over time. “Indoor tendencies” inversely predicted time outdoors among younger and older boys, and younger girls. Social opportunities positively predicted time outdoors among younger boys, while “outdoor tendencies” positively predicted time outdoors among older boys. Parental encouragement for activity positively predicted time outdoors among younger and older girls, while lack of adult supervision for active play outdoors after school inversely predicted time outdoors among older girls and older boys. Conclusion Individual (indoor and outdoor tendencies) and social factors (social opportunities, parental encouragement and parental supervision) predicted children's time outdoors over 5 years. Interventions targeting reduced indoor tendencies, increased outdoor play with others, and increased parental encouragement and supervision are warranted.
PARAMETERIZATION OF TEMPERATURE PERCEPTION OF VENTILATION CHANGES IN FULL-FACE MOTORCYCLE HELMETS

INTRODUCTION Temperature perception and thermal comfort of headgear have most often been studied with thermal manikin headforms. An underlying assumption of these measurements is that of a direct relationship between thermal perception of subjects and a measure obtained from such headforms (e.g. heat loss, temperature, heat flux, or airflow). Several studies found that in warm environments the categorization of headgear based on manikin headform measurements is comparable to the categorization based on temperature perception or thermal comfort by human subjects [1-4], supporting this assumption. A clear understanding of the sensitivity of subjects to heat transfer fluctuations has yet to be achieved. This study aimed to evaluate which parameters related to air flow and heat transfer predict the response behavior of subjects while operating the ventilation system of motorcycle helmets, focusing on the scalp section.