Positive Counterparts Research Articles

Together in bad times? Connectedness and spillovers in recession and boom

Is connectedness across countries dependent on the state of the economy? We answer this question by applying the Diebold‐Yilmaz index in a non‐linear framework. Via a Threshold VAR model, we measure the connectedness of industrial production, inflation and financial variables for seven advanced economies. We find that global connectedness is sizable and business cycle dependent. Specifically, our results suggest that higher values are recorded during recessions. Financial and nominal connectedness display different dynamics relative to the connectedness in industrial production. We also show that negative shocks cause a bigger increase in global connectedness compared to their positive counterparts. In addition, while Europe appears to be vulnerable to shocks originated in USA and Japan, the US is unaffected by shocks occurring elsewhere. Results are robust to an alternative state‐dependent modelling of the parameters and our model fit outperforms both the linear VAR and the Smooth Transition VAR.

EVALUATION OF ANTIDIABETIC AND ANTIOXIDANT EFFECTS OF ETHANOLIC LEAF EXTRACT OF ERYTHRINA ABBYSINICA LAM, EX DC

Objective: This study was conducted to scientifically evaluate the antidiabetic and antioxidant effects of ethanolic leaf extract of Erythrina abbysinica (EEA).Methods: Acute and sub-chronic effects of EEA at 100, 200, and 400 mg/kg/bwt and glibenclamide (GL) at 5 mg/kg/bwt. were evaluated in both normal and streptozotocin (STZ)-induced diabetic male Wistar rats (250–300 g). The acute studies were performed using oral glucose tolerance test (OGTT). In sub-chronic studies, animals were orally administered with EEA and GL daily for 6 w. Brine shrimp assay was used to determine the toxicity of EEA. 1, 1-diphenyl-2-picrylhydrazyl, ferric reducing capacity of plasma, and thiobarbituric acid reactive substances assays were used to determine antioxidant properties of EEA.Results: Following OGTT, EEA significantly (p<0.05) and dose-dependently (100, 200, and 400 mg/kg/bwt) decreased blood glucose levels in both normal and STZ-induced diabetic rats when compared with positive and negative control counterparts at all-time points, whereas GL significantly (p<0.05) decreased blood glucose only in normal rats but not in diabetic rats. Daily, oral administration of EEA for 6 w significantly (p<0.05) and dose-dependently (100, 200, and 400 mg/kg/bwt) decreased blood glucose levels in STZ-induced diabetic rats when compared with the diabetic control group. EEA revealed weak toxicity with a lethal concentration50 value of 997 μg/ml). Furthermore, EEA showed significant free radical scavenging, total antioxidant, and anti-lipid peroxidative capacities.Conclusion: The study has shed more light on the scientific basis for the use of E. abbysinica in management of diabetes in some communities of Eastern Cape of South Africa.

Topological negative refraction of surface acoustic waves in a Weyl phononic crystal.

Reflection and refraction of waves occur at the interface between two different media. These two fundamental interfacial wave phenomena form the basis of fabricating various wave components, such as optical lenses. Classical refraction-now referred to as positive refraction-causes the transmitted wave to appear on the opposite side of the interface normal compared to the incident wave. By contrast, negative refraction results in the transmitted wave emerging on the same side of the interface normal. It has been observed in artificial materials1-5, following its theoretical prediction6, and has stimulated many applications including super-resolution imaging7. In general, reflection is inevitable during the refraction process, but this is often undesirablein designing wave functional devices. Here we report negative refraction of topological surface waves hosted by a Weyl phononic crystal-an acoustic analogue of the recently discovered Weyl semimetals8-12. The interfaces at which this topological negative refraction occurs are one-dimensional edges separating different facets of the crystal. By tailoring the surface terminations of the Weyl phononic crystal, constant-frequency contours of surface acoustic waves can be designed to produce negative refraction at certain interfaces, while positive refraction is realized at different interfaces within the same sample. In contrast to the more familiar behaviour of waves at interfaces, unwanted reflection can be prevented in our crystal, owing to the open nature of the constant-frequency contours, which is a hallmark of the topologically protected surface states inWeyl crystals8-12.

Regulation of innate and adaptive antitumor immunity by IAP antagonists.

Inhibition of the T-cell co-inhibitory checkpoint receptors or their ligands CTLA-4, PD-1 and PD-L1 using monoclonal antibodies has proven to be highly effective against many cancers. Yet many cancers remain resistant to checkpoint blockade, and durable remissions occur in only a minority of patients. Novel approaches to enhancing antitumor responses are thus necessary in order to expand the reach of these treatments. The inhibitor of apoptosis (IAP) protein family comprises a diverse group of proteins, many of which have immunoregulatory roles. Small molecule IAP antagonists have been developed and are undergoing early phase clinical testing. These drugs were initially developed to promote tumor cell apoptosis; however, a considerable body of work now indicates that IAP antagonists induce antitumor activity through modulation of innate and adaptive immunity. Primarily through inhibition of cellular (c)-IAP1 and c-IAP2, IAP antagonists can activate alternative NF-κB signaling, promoting B-cell survival, activation of dendritic cells and delivering a broad co-stimulatory signal to T cells. At the same time, IAP antagonists can promote tumor cell intrinsic sensitization to innate immune signals, and enhance tumor cell killing by inflammatory cytokines and phagocytic macrophages. These drugs thus represent an attractive investigational approach to immunotherapy, providing a positive signaling counterpart to the relief of signal inhibition conferred by checkpoint blockade.

Alternative Patterning Methods for Paper-based Analytical Devices Using Nail Polish as a Hydrophobic Reagent

A rapid, easy, and cost effective fabrication method for paper-based analytical devices (PADs) is described. This newly developed method is based on the use of nail polish as an alternative hydrophobic reagent, and the nail polish was resistant to basic and organic solvents. Three approaches for fabrication of paper-based analytical devices (PADs) were investigated, namely writing, stamping, and spraying. The writing approach was carried out by drawing the hydrophobic area of a pre-designed pattern on filter paper with a simple lab-made pen filled with nail polish as the hydrophobic agent. The stamping and spraying approaches required the use of a designed mask, which was made by laser cutting of the magnet rubber sheet. With laser cutting, two types of templates were made, i.e., positive and negative counterparts. The positive counterpart was the inside pattern and the negative counterpart was the outside pattern of the magnet sheets. For the stamping approach, the negative counterpart of the magnet rubber mask was attached onto a simple rubber stamper that was then stamped onto filter paper after loading with nail polish solution. With the spraying method, the positive counterpart was used to cover the hydrophilic area on the paper. Then, the nail polish solution was used with an air brush and sprayed on the paper covered with the magnet rubber mask. All approaches were cost effective and required neither extra equipment nor any pretreatment step. Among all three methods, however, the spraying method was found most suitable for mass production and provided the best resolution when compared with the other two approaches. With this approach, the actual channel widths obtained were similar to the designed widths, with the narrowest possible channel width of 650 μm. Furthermore, a nail polish-treated PAD was prepared by soaking the paper in the nail polish solution. The ability of the nail polish-treated PAD was examined for its resistance to a strong basic solution and an organic solvent (up to 30% ethanol and dichloromethane). The nail polish-treated paper also showed the potential to be used as an organic-aqueous separator.

Magnetic dipole moments of the negative parity J^{PC}=2^{--} mesons in QCD

Magnetic dipole moments of the negative parity light and heavy tensor mesons are calculated within the light cone QCD sum rules method. The results are compared with the positive parity counterparts of the corresponding tensor mesons. The results of the analysis show that the magnetic dipole moments of the negative parity light mesons are smaller compared to those of the positive parity mesons. Contrary to the light meson case, magnetic dipole moments of the negative parity heavy mesons are larger than the ones for the positive parity mesons.

An In-Vivo Investigation of the Cardio-Protective Potential of Aspirin, β-oestradiol and Calcipotriol for Trastuzumab Treatment of Her-2 Positive Breast Cancer

The 15-25% of breast cancers that overexpress human epidermal growth factor receptor type 2 (Her-2) are aggressive and more difficult to treat with conventional chemotherapy than their oestrogen receptor positive (ER+) counterparts. Adjuvant trastuzumab, a specific Her-2 targeting monoclonal antibody, has significantly improved the prognosis of women with metastatic and early Her-2 positive breast cancer. Yet clinically relevant cardio-toxicity continues to undermine its gains. This study investigated the unexplored potential of aspirin, β-oestradiol and calcipotriol to attenuate the antibody’s cardio-toxicity in an adult female Balb/c mouse model using serial echocardiography to assess left ventricular function at baseline and after treatment. Mean changes in left ventricular function were compared within and between treatment groups. Trastuzumab demonstrated statistically significant left ventricular dysfunction, detectable by reductions in speckle tracking echocardiographic parameters (global radial strain) from baseline. Calcipotriol did not abrogate these cardio-toxic effects. Conversely, β-oestradiol, high and low dose aspirin attenuated these early and subtle signs of trastuzumab-induced cardiac dysfunction. The findings of this pilot study suggest that β-oestradiol or aspirin may provide cardio-protection against trastuzumab in-vivo, and larger definitive studies are justified.

Exchange traded funds: leverage and liquidity

ABSTRACTThis paper examines the differences between leveraged and unleveraged Exchange Traded Funds (ETFs), particularly for liquidity and volatility characteristics. The impact of leverage on intraday liquidity (spread and depth) is analysed in two periods – one of normal volatility and the other of abnormal/high volatility. There is a significant difference in spread and depth of leveraged and unleveraged ETFs in periods of both normal volatility and high volatility; however, this difference is more pronounced in higher volatility periods. In high volatility periods, liquidity typically diminishes in all ETFs, and this is even more so for the leveraged ETFs. When leveraged ETFs are segregated into multiples based on their power to replicate the underlying benchmark (i.e. multiples of −3, −2, −1, 2, 3), the difference in spreads between normal and high volatility periods is typically larger. The double-leveraged ETF has the most significant difference between the positive and negative counter parts. However, the relationship in the progression of the multiples does not change linearly to correspond with the level of volatility. This may be due to the nonlinear relation between volume and volatility. We shed light on the magnification effect of financial leverage on microstructure of the ETFs.

Comparison of HLA-G and MMP transcription in human tumor cell lines.

HLA-G antigens and matrix metalloproteinases (MMPs) expressed in various tumors are involved in tumor growth and metastasis. In this study, we investigated if correlation between HLA-G and MMP expression exists in different cell lines. We examined MMP transcription in two choriocarcinoma cell lines: JEG-3 (HLA-G positive) and JAR (HLA-G negative). We discovered that both cell lines express a similar panel of MMPs; except for MMP12. Transcript MMP12 was exclusively detected in HLA-G expressing JEG-3 cells but not in HLA-G deficient JAR cells. We observed HLA-G expression but no MMP12 transcription following 5-aza-2´-deoxycytidine (AZA) treatment of JAR cells. We then investigated HLA-G and MMP transcription in several human leukaemia cell lines. Leukaemia cells (lacking HLA-G expression) were converted to their HLA-G positive counterparts by AZA-treatment or by HLA-G transfection. It was found no correlation between HLA-G and MMP transcription in any examined leukaemia cell lines. The up-regulation of some MMPs and tissue inhibitors of matrix metalloproteinases (TIMPs) was observed following AZA-treatment.

I Don't Know. The Effect of Question Polarity on No-opinion Answers

A new type of political attitude survey that has gained popularity in Europe and in the United States is the voting advice application (VAA). VAAs provide users with a voting advice based on their answers to a set of attitude questions. In the calculation of this advice, no-opinion answers are excluded. We tested the hypothesis that negative VAA questions lead to more no-opinion answers than their positive equivalents. In a field experiment, visitors (N=41,505) of a VAA developed for the municipality of Utrecht in the Netherlands, were randomly guided to one of the versions of the tool in which the polarity of 16 questions was manipulated. Results do not show an overall effect of question polarity. This overall null finding appears to be caused by contrasting effects for two subtypes of negative questions: Explicit negatives (e.g. not allow) yield more no-opinion answers than their positive counterparts (e.g. allow) do, while the reverse holds for implicit negatives (e.g. forbid).

Diversity of trion states and substrate effects in the optical properties of an MoS2 monolayer

Almost all experiments and future applications of transition metal dichalcogenide monolayers rely on a substrate for mechanical stability, which can significantly modify the optical spectra of the monolayer. Doping from the substrate might lead to the domination of the spectra by trions. Here we show by ab initio many-body theory that the negative trion (A−) splits into three excitations, with both inter- and intra-valley character, while the positive counterpart (A+) consists of only one inter-valley excitation. Furthermore, the substrate enhances the screening, which renormalizes both band gap and exciton as well as the trion-binding energies. We verify that these two effects do not perfectly cancel each other, but lead to red-shifts of the excitation energies for three different substrates ranging from a wide-bandgap semiconductor up to a metal. Our results explain recently found experimental splittings of the lowest trion line as well as excitation red-shifts on substrates.

Cracking of quasi-brittle structures under monotonic and cyclic loadings: A d+/d− damage model with stiffness recovery in shear

In the present paper, a new d+/d− damage model apt for quasi-brittle materials is described and its validation is carried out considering unreinforced concrete, reinforced concrete and masonry elements.Two independent scalar damage variables, d+ and d−, in combination with the split of the reversible strain tensor into its positive and negative counterparts, are adopted in order to simulate the pronounced dissimilar response under tension and compression, typical of these materials. An energy-equivalent framework is considered for representing the orthotropy induced in the material by the degradation process, with the consequence that a thermodynamically consistent constitutive operator, positive definite, symmetric and strain-driven, is derived. In addition to the degradation parameters, the permanent strain tensor is also contemplated by the model and a modification of the exponential softening modulus is proposed in order to treat the evolution of the two causes of dissipation, damage and irreversible deformations, in a coupled way.The formulation is integrated with a multidirectional damage procedure, addressed to extend the microcrack closure-reopening (MCR) capabilities of the model to shear cyclic conditions, characterized by orthogonal (or however intersecting) sets of cracks. Maintaining unaltered the dependence of the constitutive law from two scalar indeces, d+ and d−, this approach activates or deactivates a tensile (compressive) damage value on the base of the current maximum (minimum) principal strain direction. In correspondence with damage activation (crack opening) or deactivation (crack closure), a smooth transition is introduced, in order to avoid abrupt changes in stiffness and enhance the numerical performance and robustness of the multidirectional procedure. The adequacy of the proposed constitutive model in reproducing experimental results has been proven for both monotonic and cyclic loading conditions. The two examples of application involving cyclic loads, dominated by shear, constitute a validation of the multidirectional damage approach, showing how the suitable representation of unilateral effects and permanent deformations is essential to model the observed structural response in terms of maximum resistance, evolution of stiffness degradation and dissipation capacity.

Rhetoric in Tooth and Claw: Animals, Language, Sensation

Rhetoric in Tooth and Claw: Animals, Language, Sensation

Expressives, Majoratives, and Ineffability

Abstract The purpose of this essay is to argue that not all instances of expressive language suffer alike from the problem of descriptive ineffability. Descriptive ineffability refers to the problem that speakers are never fully satisfied when they are asked to paraphrase sentences containing expressive terms such as `damn' using only descriptive terms. It is commonly assumed that descriptive ineffability is an important feature of all kinds of expressive language - derogatory language just as commendatory or valorizing language. However, I find that majoratives, i.e. the positive counterpart to negative expressives (pejoratives), do not exhibit the characteristic of descriptive ineffability. This finding is important both to clarify what kind of data competing theories of expressives have to explain and to shed further light on the wider phenomenon of ineffability.

Antibiotic Sensitivity Pattern of Bacteria Associated With Wound Infections in Kaduna Metropolis

Chronic wounds infections could result to structural damage and establishment of a chronic biofilm which stimulates host immune response that cause further damage generating a vicious cycle. Bacteria pathogens associated with wound infections were characterised and their resistance profile to the most common conventional antibiotics generated. Fifty (50) wound samples were collected from 50 patients and were screened on blood agar and MacConkey agar, while Mueller Hilton agar was used for the determination of antibiotics susceptibility test using kirby Bauer disc method. The predominant bacteria isolated were Staphylococcus aureus (50%) followed by Escherichia coli (36%), Pseudomonas aeruginosa (30%), Klebsiella pneumonia (16%), Streptococcus pyogenes (8%), Proteus mirabilis (4%) and least by Enterococcus feacalis (2%). Gram negative bacteria presented (58.9%) compared to their Gram positive counterpart which had 41.1% prevalence. Gram-negative bacteria were resistant to ampicillin. Gram- negative bacteria showed quite high resistant to the majority of antibiotics used in this research, while some were active against these bacteria. The antibiotics used on Gram negative bacteria in this research were; Ampicillin, Septrin, Chloramphenicol, Sparfloxacin, Ciprofloxacin, Amoxacillin, Augmentin, Gentamycin, Pefloxacin, Tarivid and Streptomycin. While for Gram positive are; Ampicilin, Pefloxacin, Gentamycin, Ampiclox, Zinnacef, Recephin, Amoxacillin, Ciprofloxacin, Streptomycin, Septrin and Erythromycin. The knowledge of agents of wound infections and the antibiotic sensitivity test as was seen from this research could be viable tool in the selection of antibiotic therapy and infection control measures in public health care and policies regarding antibiotic utilization.

Salivary secretion and disgust: A pilot study

Although a direct link has been established between self-experienced disgust and salivary secretion, it is unclear whether this physiological index is modulated by the social experience of disgust (i.e., exposure to the facial expression of disgust). We tested this issue in a pilot study by collecting salivary samples in a group of 20 healthy humans watching pictures of faces expressing disgust. Moreover, we tried to replicate previous evidence by testing saliva secretion in response to pictures of unpalatable (i.e., rotten) food and non-gustatory disgusting stimuli (i.e., disgusting insects). Overall, our analysis shows a general reduction of saliva secretion in response to disgust stimuli, compared to their positive counterparts, although further analyses for specific stimulus categories indicated that this difference was statistically significant only for food pictures. The non-significance of the face and insect categories might be due to insufficient power of our small sample. Overall, a general reduction of saliva secretion for different disgust-related stimuli suggests a shared mechanism of encoding, in line with theories of neural reuse.

Kinetic theory of dark solitons with tunable friction.

We study controllable friction in a system consisting of a dark soliton in a one-dimensional Bose-Einstein condensate coupled to a noninteracting Fermi gas. The fermions act as impurity atoms, not part of the original condensate, that scatter off of the soliton. We study semiclassical dynamics of the dark soliton, a particlelike object with negative mass, and calculate its friction coefficient. Surprisingly, it depends periodically on the ratio of interspecies (impurity-condensate) to intraspecies (condensate-condensate) interaction strengths. By tuning this ratio, one can access a regime where the friction coefficient vanishes. We develop a general theory of stochastic dynamics for negative-mass objects and find that their dynamics are drastically different from their positive-mass counterparts: they do not undergo Brownian motion. From the exact phase-space probability distribution function (i.e., in position and velocity), we find that both the trajectory and lifetime of the soliton are altered by friction, and the soliton can undergo Brownian motion only in the presence of friction and a confining potential. These results agree qualitatively with experimental observations by Aycock et al. [Proc. Natl. Acad. Sci. USA 114, 2503 (2017)] in a similar system with bosonic impurity scatterers.

Anemia and hematinic deficiencies in gastric parietal cell antibody-positive and -negative oral mucosal disease patients with microcytosis.

Microcytosis is defined as mean corpuscular volume (MCV)<80 fL. This study assessed the anemia statuses and hematinic deficiencies in 30 patients with gastric parietal cell antibody-positive microcytosis (GPCA+/microcytosis) and 210 patients with GPCA-negative microcytosis (GPCA-/microcytosis). We measured and compared the mean red blood cell (RBC) count, MCV, and RBC distribution width (RDW), as well as blood levels of hemoglobin, iron, vitamin B12, folic acid, and homocysteine among the aforementioned patient groups and 240 healthy controls. Compared with GPCA-/microcytosis, the positive counterparts presented with a lower mean serum vitamin B12 level (marginal significance), significantly higher mean RDW and serum homocysteine level, and significantly greater frequencies of vitamin B12 deficiency and high homocysteine level. GPCA-/microcytosis patients had significantly greater frequencies of hemoglobin, iron, vitamin B12, and folic acid deficiencies and of RBC count >5×1012/L than healthy controls. Moreover, 19 of 30 GPCA+/microcytosis patients and 143 of 210 GPCA-/microcytosis patients had anemia, with iron deficiency anemia being the most common type, followed by thalassemia trait-induced anemia and microcytic anemia due to other causes. We conclude that GPCA in microcytosis patients' sera may have caused significantly lower mean vitamin B12 level as well as significantly higher mean RDW and serum homocysteine level in our GPCA+/microcytosis patients than in GPCA-/microcytosis patients. Herein, iron deficiency anemia was the most common type of anemia in anemic GPCA+/microcytosis and GPCA-/microcytosis patients.

Lights … action: Comparison of trauma films for use in the trauma film paradigm

Affective films are often used in emotion research and negative films are frequently used as an analogue for trauma (trauma film paradigm). However, different films are used with possibly distinct consequences. We aimed to investigate specific effects of four negative films covering distinct themes (physical, sexual, traffic and food), and tested neutral and positive films with matching content. Self-reported emotional responses and heart rate during the films were examined (immediate responses) as well as intrusions of the films in the subsequent week (delayed responses). Within each theme, negative films were rated as more unpleasant than the positive and neutral counterparts. They also evoked more negative emotions and more intrusive memories. Across themes, the four negative films did not differ in terms of valence and arousal, but clearly differed on immediate (e.g., disgust, embarrassment, heart rate) and delayed (intrusions) effects. Thus, we urge researchers to carefully select negative films for their studies, as different films seem to evoke distinct emotional responses. In addition, using positive films within the same themes is recommended in order to control for effects of arousal. In general, the specific film material should be considered when comparing effects across studies.

Nanoboomerang-based inverse metasurfaces—A promising path towards ultrathin photonic devices for transmission operation

Metasurfaces have revolutionized photonics due to their ability to shape phase fronts as requested and to tune beam directionality using nanoscale metallic or dielectric scatterers. Here we reveal inverse metasurfaces showing superior properties compared to their positive counterparts if transmission mode operation is considered. The key advantage of such slot-type metasurfaces is the strong reduction of light in the parallel-polarization state, making the crossed-polarization, being essential for metasurface operation, dominant and highly visible. In the experiment, we show an up to four times improvement in polarization extinction for the individual metasurface element geometry consisting of deep subwavelength nanoboomerangs with feature sizes of the order of 100 nm. As confirmed by simulations, strong plasmonic hybridization yields two spectrally separated plasmonic resonances, ultimately allowing for the desired phase and scattering engineering in transmission. Due to the design flexibility of inverse metasurfaces, a large number of highly integrated ultra-flat photonic elements can be envisioned, examples of which include monolithic lenses for telecommunications and spectroscopy, beam shaper or generator for particle trapping or acceleration or sophisticated polarization control for microscopy.