Small Tail Research Articles

New Aspects of Exponential Asymptotics in Multiple‐Scale Nonlinear Wave Problems

It is known that standard multiple‐scale perturbation techniques fail to pinpoint the soliton solution branches that bifurcate at edges of bandgaps in periodic media, owing to the appearance of exponentially small growing wave tails when the soliton's envelope is not properly positioned. When the bifurcation is from a single wave mode of a band edge, this difficulty has been handled in recent work by computing these tails via an exponential asymptotics technique in the wave number domain. However, the same approach is not directly applicable to the bifurcation of solitons near the opening of a bandgap, where wave modes from two nearby band edges interact with each other. Here, we discuss two nontrivial extensions of the exponential asymptotics technique that enable resolving this issue. For simplicity, the analysis focuses on two model problems, namely, a steady‐state forced Korteweg–de Vries equation and a steady‐state forced nonlinear Schrödinger equation, with the precise form of forcing and balance between nonlinear and dispersive terms chosen so as to mimic the situation encountered in the bifurcation of solitons near a bandgap opening. Our analysis exhibits a number of new features that are significantly different from previous exponential asymptotics procedures, such as the treatments when the nonlinearity dominates dispersion and when the decay rates of the Fourier‐transformed solution are asymmetric. In addition, the analysis reveals new, and in some cases rather unexpected, functional forms for exponentially small wave tails, which are also confirmed by numerical results.

Hydrotropic Action of Cationic Hydrotrope p-Toluidinium Chloride on the Solubility of Sparingly Soluble Gliclazide Drug Molecule: A Computational Study

We perform classical molecular dynamics simulations of sparingly soluble drug gliclazide (GLC) and hydrotrope p-toluidinium chloride (PTOL) in water with a regime of PTOL concentrations. Our results demonstrate that PTOL starts to self-aggregate above its minimum hydrotrope concentration (MHC). Further, these PTOL aggregates create a mixed micellar-like framework in which the hydrophobic small tail part of most of the PTOL molecules direct toward the inside, whereas in order to make favorable contact with water molecules its hydrophilic ammonium group points outward. But, in order to make hydrogen bonds with GLC molecules, the polar groups of a few of the hydrotropes direct inward also. This provides an environment for the incorporation of the drug molecules into the mixed environment (hydrophobic as well as hydrophilic core) of PTOL clusters. The average number of hydrogen bond calculations indicates that PTOL aggregate does not have much effect on the average number of water-PTOL hydrogen bonds, but it has an influence on the average number of water-GLC, GLC-GLC, and GLC-PTOL hydrogen bonds. Both electrostatic and van der Waals energy components of drug and hydrotrope interactions play vital roles in the solubilization process. Furthermore, the estimation of Flory-Huggins interaction parameters also suggests favorable interactions between hydrotrope PTOL and GLC drug molecules.

A new species of Rhinophis Hemprich, 1820 (Serpentes: Uropeltidae) from the central hills of Sri Lanka.

A new species of uropeltid snake, Rhinophis roshanpererai sp. nov., is described based on three specimens from Badulla District, Sri Lanka. The new species is distinguished from its congeners by the number of dorsal scale rows and ventral scales, a colour pattern that lacks pale stripes, and by having a very small tail shield with four or three prominent spines. Based on lack of records from similar habitats and elevations elsewhere in Sri Lanka, the new species likely has a very small range in the central highlands. The description of the new species brings the total nominal species of Rhinophis to 20, with four of the 16 Sri Lankan species having been described since 2009.

Size and Origins of Long-Range Orientational Water Correlations in Dilute Aqueous Salt Solutions.

Long-range ordering of water around solutes has been repeatedly invoked as the key to its biological function. Recently, it has been shown that in an 8 mM aqueous NaCl solution the orientational correlation between water molecules extends beyond 8 nm. This was interpreted as arising from ion-induced long-range effects on the water collective hydrogen-bond interactions. Each ion was suggested to affect >10 000 water molecules, leading to a picture involving nanoscopic "ordered domains". Using molecular dynamics simulations, we show that the very small long-range tail in the correlation function is caused primarily by pairs of water molecules belonging to different ions' hydration shells and can be made to practically disappear by rearranging the ionic positions. This means that the ion-induced water orientational ordering in millimolar salt solutions cannot be separated from ion-ion interaction effects, for which the Debye-Hückel screening length shrinks to less than 1 nm at physiological ionic strengths.

Clumpy galaxies seen in H α: inflated observed clump properties due to limited spatial resolution and sensitivity

High-resolution simulations of star-forming massive galactic discs have shown that clumps form with a characteristic baryonic mass in the range $10^7-10^8~M_{\odot}$, with a small tail exceeding $10^9~M_{\odot}$ produced by clump-clump mergers. This is in contrast with the observed kpc-size clumps with masses up to $10^{10}~M_{\odot}$ in high-redshift star-forming galaxies. In this paper we show that the comparison between simulated and observed star-forming clumps is hindered by limited observational spatial resolution and sensitivity. We post-process high-resolution hydrodynamical simulations of clumpy discs using accurate radiative transfer to model the effect of ionizing radiation from young stars and to compute H$\alpha$ emission maps. By comparing the intrinsic clump size and mass distributions with those inferred from convolving the H$\alpha$ maps with different gaussian apertures, we mimick the typical resolution used in observations. We found that with 100 pc resolution, mock observations can recover the intrinsic clump radii and stellar masses, in agreement with those found by lensing observations. Instead, using a 1 kpc resolution smears out individual clumps, resulting in their apparent merging. This causes significant overestimations of the clump radii and, therefore, masses derived using methods that use their observed sizes. We show that limited sensitivity can also force observations to significantly overestimate the clump masses. We conclude that a significant fraction of giant clumps detected in the observations may result from artificially inflated radii and masses, and that $\approx 100$ pc spatial resolution is required to capture correctly the physical characteristics of star-forming clumps if they are coherent structures produced by disc fragmentation.

Current International Economic Scenario and India

Now the current economic scenario is not in bright side. In 2016 when the world economy was in mess, the commodity market was crashing. Stagnant global trade, subdued investment and heightened policy uncertainty marked another difficult year for the world economy. Global growth in 2016 is estimated at post crisis low of 2.3% and is projected to rise to 2.7% in 2017. The global economy has now entered its sixth year of stagnation and the growth outlook for 2017 shows a continuation of this trend. A projected stabilization in energy and commodity prices may provide a small tail wind for resource rich economies in 2017, but the medium-term trend continues to be dominated by weaker growth in key inputs notably investment and labour supply. Modest positive signals emerge from base scenario showing some strengthening in qualitative growth factors such as more advanced technology, improved labour force skills and greater productivity. But those potentially favourable factors are under pressure from ongoing political, policy and economic uncertainties around the world. Businessmen have to prepare for more disruptions from geopolitical tensions, policy uncertainty, financial market volatility and rapid changes in technology. India is also facing same problems but its robust economy able to counter all these problems. It is one of the bright spot in the world economy. Still it has many problems in current scenario.

Big Data, Small Sample.

Multiple comparisons and small sample size, common characteristics of many types of "Big Data" including those that are produced by genomic studies, present specific challenges that affect reliability of inference. Use of multiple testing procedures necessitates calculation of very small tail probabilities of a test statistic distribution. Results based on large deviation theory provide a formal condition that is necessary to guarantee error rate control given practical sample sizes, linking the number of tests and the sample size; this condition, however, is rarely satisfied. Using methods that are based on Edgeworth expansions (relying especially on the work of Peter Hall), we explore the impact of departures of sampling distributions from typical assumptions on actual error rates. Our investigation illustrates how far the actual error rates can be from the declared nominal levels, suggesting potentially wide-spread problems with error rate control, specifically excessive false positives. This is an important factor that contributes to "reproducibility crisis". We also review some other commonly used methods (such as permutation and methods based on finite sampling inequalities) in their application to multiple testing/small sample data. We point out that Edgeworth expansions, providing higher order approximations to the sampling distribution, offer a promising direction for data analysis that could improve reliability of studies relying on large numbers of comparisons with modest sample sizes.

Gastrointestinal nematodes infections and anthelmintic resistance in grazing sheep in the Eastern Inner Mongolia in China.

Gastrointestinal nematodes (GIN) are a crucial restraint to grazing sheep production worldwide. This study was conducted to determine the infections and anthelmintic resistance (AR) of GIN in pasture-based sheep in the Eastern Inner Mongolia, China. GIN eggs were tested from 600 grazing sheep feces of 10 farms using saturated saline flotation method and McMaster's method. The egg hatch test (EHT) and the faecal egg count reduction test (FECRT) were used to evaluate resistance of GIN to anthelmintics. We found that the average infection rate was 79.2% (range: 45%-100%). The grand mean faecal egg count (FEC) was 1813.2 eggs per gram (EPG) (range: 0-32400 EPG). There were significant differences in GIN infection among different breeds of sheep. The sequence of infection intensity and infection rate were Small fat tail > Ujimqin > Ju Ud (p<0.05). The 50% effective doses (ED50) of albendazole(ABZ) and levamisole (LMS) for expelling were 5.670 µg/mL and 0.302 µg/mL, respectively. The percentage reductions of avermectin (AVM), ivermectin (IVM), ABZ and LMS were 81.28%, 86.49%, 76.21% and 96.59%, respectively. The most predominant parasite genus in all four anthelmintics was Haemonchus. In these tested areas, mixed infections of GIN in grazing sheep were very common. AR, especially in Haemonchus, was a serious problem in these sheep flocks. Thus, actions are urgently required to taken to mitigate the worsening situation.

Did Phaethon father the Geminids?

Meteoroid Streams Meteor showers are caused by Earth passing through a stream of debris left by a comet. The Geminids shower seems to originate from (3200) Phaethon, but that is an asteroid, not a comet, with an unusual elliptical orbit that takes it close to the Sun. Hui and Li examined images of Phaethon as it passed the Sun in August 2016, showing that it generated a small tail. Although this comet-like behavior could feed the meteor stream, the mass of material ejected is far too small. If Phaethon is indeed the origin of the Geminids, it must have been much more active in the recent past. Astron. J. 153 , 23 (2017).

Accurate Small Tail Probabilities of Sums of iid Lattice-Valued Random Variables via FFT

ABSTRACTAccurately computing very small tail probabilities of a sum of independent and identically distributed lattice-valued random variables is numerically challenging. The only general purpose algorithms that can guarantee the desired accuracy have a quadratic runtime complexity that is often too slow. While fast Fourier transform (FFT)-based convolutions have an essentially linear runtime complexity, they can introduce overwhelming roundoff errors. We present sisFFT (segmented iterated shifted FFT), which harnesses the speed of FFT while retaining control of the relative error of the computed tail probability. We rigorously prove the method’s accuracy and we empirically demonstrate its significant speed advantage over existing accurate methods. Finally, we show that sisFFT sacrifices very little, if any, speed when FFT-based convolution is sufficiently accurate to begin with. Supplementary material is available online.

Endoscopic ultrasound-guided ethanol ablation for functioning insulinoma

Background:Most diagnosed pancreatic neuroendocrine tumors (pNETs) are nonfunctioning tumors (90.8%); the remaining 9% are malignant functioning tumors. While surgical resection is the standard of care, alternative management options may be mandated in symptomatic patients who refuse or are ineligible for surgery. We present a case of endoscopic ultrasound (EUS)-guided ethanol ablation of symptomatic insulinoma in a patient who refused surgery.Case Presentation:A 35-year-old man was referred to our facility with suspected insulinoma for EUS evaluation. During a 48-h supervised fast, a plasma glucose of 30 mg/dl was obtained with a corresponding serum insulin level of 235 μIU/mL (normal: 20–80) and C-peptide level of 19.9 ng/mL (normal: 2.8–9.9). Computed tomography abdomen revealed a normal pancreas with no detected masses. On admission, he was on intravenous glucose 25% at an infusion rate of 250 mL/h and octreotide (150 mcg subcutaneously three times daily). EUS examination revealed a small hypoechoic pancreatic tail mass 2 cm ×1.5 cm with no vascular involvement or detected lymph nodes. EUS-fine needle aspiration was done using a 25G needle. Pathological examination was consistent with NET. The patient's family initially refused surgery; EUS-guided ethanol ablation was therefore considered. The lesion was injected with 3 mL of ethanol using 25G needle resulting in a hyperechoic blush within the center of the tumor. Following the procedure, there was partial clinical success with the patient's glucose infusion rate decreased to 100 mL/h. After 3 days, a second session was considered. The lesion was re-injected with 3 mL of ethanol using 22G needle resulting in a hyperechoic blush of the lesion. Again, there was partial clinical success with the patient's glucose infusion rate decreased to 50 mL/h. There were no postprocedural complications. The patient's family decided to do surgery and distal pancreatectomy was done.Discussion:EUS-guided ethanol ablation of functioning pNETs is a less common therapeutic tool. A recent literature review showed 19 patients who underwent EUS-guided ethanol ablation of functioning pNETs from 2006 to 2015 with technical and clinical success in 100% of cases. This case reports another EUS-guided ethanol ablation of functioning insulinoma added to the documented cases, with partial clinical success. Despite partial clinical success, EUS-guided ethanol ablation is feasible and safe when applied to symptom relief in functioning tumors in patients who refuse or are ineligible for surgery.

Dipeptidyl Peptidase-IV Inhibition for the Treatment of Cardiovascular Disease - Recent Insights Focusing on Angiogenesis and Neovascularization.

Dipeptidyl peptidase IV (DPP-IV) is a complex enzyme that acts as a membrane-anchored cell surface exopeptidase and transmits intracellular signals through a small intracellular tail. DPP-IV exists in human blood in a soluble form, and truncates a large number of peptide hormones, chemokines, cytokines, and growth factors in vitro and in vivo. DPP-IV has gained considerable interest as a therapeutic target, and a variety of DPP-IV inhibitors that prolong the insulinotropic effects of glucagon-like peptide-1 (GLP-1) are widely used in clinical settings as antidiabetic drugs. Indeed, DPP-IV is upregulated in proinflammatory states, including obesity and cardiovascular disease with and without diabetes mellitus. Consistent with this maladaptive role, DPP-IV inhibitors seem to exert a protective role in cardiovascular disease. In addition to their GLP-1-dependent vascular protective actions, DPP-IV inhibitors exhibit GLP-1-independent beneficial effects on angiogenesis/neovascularization via several signaling pathways (e.g., stromal cell-derived factor-1α/C-X-C chemokine receptor type-4, vascular endothelial growth factor-A/endothelial nitric oxide synthase, etc.). This review focuses on recent findings in this field, highlighting the role of DPP-IV in therapeutic angiogenesis/neovascularization in ischemic heart disease and peripheral artery disease.

Molecular analysis of CIB4 gene and protein in Kermani sheep.

The human calcium- and integrin-binding protein (CIB) family is composed of CIB1, CIB2, CIB3, and CIB4 proteins and the CIB4 gene affects fertility. Kermani sheep is one of the most important breeds of Iranian sheep breeds. The aim of this study was to analyze for the first time molecular characteristics of the CIB4 gene and protein in Kermani sheep. Different tissues were collected from the Kermani sheep and real time PCR was performed. The PCR products were sequenced, comparative analyses of the nucleotide sequences were performed, a phylogenetic tree was constructed, and different characteristics of CIB4 proteins were predicted. Real time PCR results showed that the CIB4 gene is expressed only in testis of Kermani sheep. The cDNA nucleotide sequence was identical with small tail Han sheep, cattle, goat, camel, horse, dog, mouse and human, respectively 100, 99, 99, 98, 98, 96, 96, and 96%. Hence, it can be suggested that the CIB4 gene plays a role in male fertility. Based on the phylogenetic analysis, sheep CIB4 gene has a close relationship with goat and cattle first, and then with camel and whale. Although we demonstrated that CIB4 is a testis-specific gene, expressed only in the testis and it interacts with other proteins, the mechanisms by which CIB4 expression is regulated need to be elucidated.

Effects of various stocking rates on grassland soil respiration during the non-growing season

Soil respiration is a key component of net CO2 exchange in grassland ecosystems and directly influences the soil carbon pool dynamics. While numerous soil respiration studies in grazed grasslands exist, the accurate quantification of the net CO2 exchange in grassland ecosystems throughout the entire year is required to determine whether grazed grasslands are carbon sinks or sources. In this study, we evaluated how stocking rate influenced soil respiration during the non-growing season in a typical grassland in the Hebei Province of North China. To examine the effects of stocking rate on soil respiration, soil respiration rates were measured using a soil greenhouse gas flux measurement system. Three stocking rates—ungrazed control (UG), moderate grazing (MG), and heavy grazing (HG)—were applied by grazing small tail sheep (ewes and lambs) at different densities from the end of June to early October in 2010 through 2013, and the relationships among soil respiration, stocking rate, and environmental factors were analyzed during the non-growing season (1 October 2013 to 30 April 2014). Variation in soil respiration followed a “V” pattern and was correlated with soil temperature and moisture for all stocking rates. Stocking rates did not significantly influence soil temperature or soil moisture; however, cumulative CO2 emissions during the non-growing season decreased dramatically (P<0.05) with increased stocking rates, following the order of UG (0.51±0.015kgCm−2)>MG (0.38±0.012kgCm−2)>HG (0.33±0.009kgCm−2). The influences of air and soil temperature on soil respiration rate were best described by an exponential equation (R2=0.43–0.55; P<0.01). A significant quadratic relationship was found between soil moisture and soil respiration rate (R2=0.46–0.67; P<0.01). Soil respiration during the non-growing season was most strongly influenced by air temperature (R2=0.56), with Q10values either increasing or decreasing relative to the UG treatment for the MG and HG treatment, respectively. Given the strong influence of grazing intensity on soil respiration in this grassland ecosystem, we suggest that the accurate estimates of annual soil respiration should routinely account for soil respiration during the non-growing season.

Ovarian transcriptomic study reveals the differential regulation of miRNAs and lncRNAs related to fecundity in different sheep

miRNAs and lncRNAs, which represent one of the most highly expressed classes of ncRNAs in development, are attracting increasing interest. A variety of regulators is considered to be implicated in sheep species with different fecundity. However, interactions between miRNAs and lncRNAs and changes in the expression of regulatory lncRNAs in sheep fecundity have not yet been reported. To characterize the important roles of miRNAs and lncRNAs and elucidate their regulating networks in sheep prolificacy, a genome-wide analysis of miRNAs and lncRNAs from Small Tail Han sheep of genotypes FecBBFecBB (Han BB) and FecB+ FecB+ (Han++) and from Dorset sheep (Dorset) was performed. An integrated analysis of miRNAs and lncRNAs was performed to study the regulatory function of miRNAs and lncRNAs in fecundity, revealing significantly correlated patterns of expression. Dramatic changes of miRNAs and lncRNAs suggest their critical roles in sheep fecundity. In conclusion, this is the first study performing thorough investigations of regulatory relationships among lncRNAs, miRNA and mRNAs, which will provide a novel view of the regulatory mechanisms involved in sheep fecundity. These results may provide further insight into sheep fecundity and help us to improve sheep prolificacy.

Small Cystic Pancreatic Tail Malignancy Presenting with Cerebellar Metastases in the Absence of Liver and Lung Involvement

Small Cystic Pancreatic Tail Malignancy Presenting with Cerebellar Metastases in the Absence of Liver and Lung Involvement

Spin morphologies and heat dissipation in spherical assemblies of magnetic nanoparticles

Aggregates of magnetic nanoparticles (MNPs) exhibit unusual properties due to the interplay of small system size and long-range dipole-dipole interactions. Using the micromagnetic simulation software oommf, we study the spin morphologies and heat dissipation in micron-size spherical assemblies of MNPs. In particular, we examine the sensitivity of these properties to the dipolar strength, manipulated by the interparticle separation. As oommf is not designed for such a study, we have incorporated a novel scaling protocol for this purpose. We believe that it is essential for all studies where volume fractions are varied. Our main results are as follows: (i) Dense assemblies exhibit strong dipolar effects which yield local magnetic order in the core but not on the surface, where moments are randomly oriented. (ii) The probability distribution of ground-state energy exhibits a long high-energy tail for surface spins in contrast to small tails for the core spins. Consequently, there is a wide variation in the energy of surface spins but not the core spins. (iii) There is strong correlation between ground-state energy and heating properties on application of an oscillating magnetic field $h(t)={h}_{o}cos2\ensuremath{\pi}ft$: the particles in the core heat uniformly, while those on the surface exhibit a wide range from cold to intensely hot. (iv) Specific choices of ${h}_{o}$ and $f$ yield characteristic spatial heat distributions, e.g., hot surface and cold core, or vice versa. (iv) For all values of ${h}_{o}$ and $f$ that we consider, heating was maximum at a specific volume fraction. These results are especially relevant in the context of contemporary applications such as hyperthermia and chemotherapy, and also for novel materials such as smart polymer beads and superspin glasses.

Comparative transcriptome profiling of longissimus muscle tissues from Qianhua Mutton Merino and Small Tail Han sheep.

The Qianhua Mutton Merino (QHMM) is a new sheep (Ovis aries) variety with better meat performance compared with the traditional local variety Small Tail Han (STH) sheep. We aimed to evaluate the transcriptome regulators associated with muscle growth and development between the QHMM and STH. We used RNA-Seq to obtain the transcriptome profiles of the longissimus muscle from the QHMM and STH. The results showed that 960 genes were differentially expressed (405 were up-regulated and 555 were down-regulated). Among these, 463 differently expressed genes (DEGs) were probably associated with muscle growth and development and were involved in biological processes such as skeletal muscle tissue development and muscle cell differentiation; molecular functions such as catalytic activity and oxidoreductase activity; cellular components such as mitochondrion and sarcoplasmic reticulum; and pathways such as metabolic pathways and citrate cycle. From the potential genes, a gene-act-network and co-expression-network closely related to muscle growth and development were identified and established. Finally, the expressions of nine genes were validated by real-time PCR. The results suggested that some DEGs, including MRFs, GXP1 and STAC3, play crucial roles in muscle growth and development processes. This genome-wide transcriptome analysis of QHMM and STH muscle is reported for the first time.

On Dipole Moments and Hydrogen Bond Identification in Water Clusters

It is demonstrated that the localized orbitals calculated for a water cluster have small delocalization tails along the hydrogen bonds, that are crucial in determining the resulting dipole moments of the system. (By cutting them, one gets much smaller dipole moments for the individual monomers-close to the values one obtains by using a Bader-type analysis.) This means that the individual water monomers can be delimited only in a quite fuzzy manner, and the electronic charge density in a given point cannot be assigned completely to that or another molecule. Thus, one arrives to the brink of breaking the concept of a water cluster consisting of individual molecules. The analysis of the tails of the localized orbitals can also be used to identify the pairs of water molecules actually forming hydrogen bonds.

Ovarian proteomic study reveals the possible molecular mechanism for hyperprolificacy of Small Tail Han sheep.

Small Tail Han sheep is a widely bred farm animal in China which has attracted lots of attention due to their high prolificacy and year-round estrus. However, the molecular mechanism of its fecundity remains unrevealed. The FecB gene polymorphism has been found to be associated with the ovulation rate and litter size of sheep. In the present study, we constructed an iTRAQ-based quantitative proteomics analysis to compare the ovarian proteomes of FecB+FecB+ genotype Small Tail Han sheep ewes (Han ++), FecBBFecBB Han ewes (Han BB) and Dorset ewes (Dorset). Hundreds of differentially expressed proteins between each two groups were identified; GO and KEGG pathway analysis indicated that the expressions of those proteins involved in ribosome assembly, protein translation and mTOR pathway between Dorset and both Han groups were highly different. Between Han ++ and Han BB groups, higher level of protein expressions were related to mitochondrial oxidation functions such as oxidoreductase activity, cytochrome-c oxidase activity and electron carrier activity. This was identified in Han BB group, which may contribute to the elevated ovulation rate of Han BB ewes. In conclusion, our work provided a prospective understanding of the molecular mechanism for high prolificacy of Small Tail Han sheep.