Smooth Tail Research Articles

Dynamics of diabatically forced anticyclonic plumes in the stratosphere

AbstractA new class of vortices has been observed in the stratosphere following extreme wildfires (Canada 2017, Australia 2020) and volcanic eruptions (Raikoke 2019). These vortices are long‐lived mesoscale anticyclones (hundreds to 1,000 km in diameter) trapping plumes of aerosols and combustion/volcanic compounds. Owing to their unusual composition, these anticyclonically trapped plumes (ATPs) are associated with a significant radiative heating, which fuels their ascent through the stratosphere. This article investigates the dynamics of ATPs using two complementary approaches: analytically, in a potential vorticity (PV) perspective, and through idealised numerical simulations with the Weather Research and Forecasting (WRF) model. In both cases, we consider the vortical flow forced by a heating Lagrangian tracer. By reformulating the problem in the potential radius–potential temperature coordinate system introduced for tropical cyclones, we first clarify that ATP formation is concomitant with the injection of air into the stratosphere at extratropical latitudes. Then, we derive a set of simplified one‐dimensional equations describing the subsequent evolution of the flow after the injection. The equation obtained for the tracer is a variant of the classical Burgers' equation. In qualitative agreement with the three‐dimensional WRF simulations, this theoretical model predicts that ATPs develop an upper tracer front associated with sustained near‐zero anticyclonic PV, followed by a smooth tracer tail of cyclonic PV. Radiative relaxation of the temperature perturbations induced by the anticyclone and the presence of an initial PV anomaly tend to stabilise ATPs during their ascent. Finally, we note that the theory predicts a similar relationship between the plume and anticyclonic PV for cooled ATPs, which is supported by three‐dimensional simulations and may apply to the 2022 Hunga volcanic plume.

Homeopathic Treatment of snakebite in dog – case report

Snakebite accidents are very common nearby forest areas. The majority of these incidents are caused by snakes of the genus Bothrops, which comprises over 45 species distributed in Central and South America. These snakes usually hunt small mammals and lizards at dusk. Snakebites from this genus generally occur in the head, limbs, and neck regions. Bothrops snakes are considered aggressive animals, characterized by inverted "V" markings along their bodies, triangular heads, smooth tails, and length ranging from 0.5m to 2m. They exhibit color variations of brown, green, and gray. Bothrops venom has necrotic, coagulating, vasculotoxic, and nephrotoxic effects, which can cause extensive necrosis at the bite site, tissue loss, and limb dysfunction, sometimes resulting in amputation. The bitten animal may experience prostration, tachypnea, localized edema and pain, petechiae, hemorrhages, and extensive necrotic areas. Hematuria, hypotension, pulmonary edema, and even death, as well as various laboratory abnormalities, may also occur. The case reported herein was attended at a veterinary clinic in Campos Altos, Minas Gerais, Brazil. It involved a mixed-breed female dog, 3 years old, weighing 4.5 kg, which had been bitten by a Bothrops snake approximately 90 minutes before. The animal presented edema and pain at the site of the bite (pelvic limb), as well as tachycardia. At once, it was administered intravenous polyvalent antiophidic serum, dexamethasone, serum, furosemide, tramadol, and ceftriaxone (antibiotic). Local treatment included corticosteroid and antibiotic ointment dressings. The animal remained stable, but after 24 hours, an extensive area with edema, hematoma, bleeding, and early necrosis at the bite site was observed, worsening with each passing hour. After 48 hours, therapy with Bothrops CH6 (5 globules every 8 hours) was initiated to reduce local effects (edema, hemorrhage, and necrosis). The animal showed rapid improvement in the appearance of the lesion, and after 5 days of treatment, there was no longer edema or bleeding, only a circumscribed cutaneous injury, which was managed with local dressings (cleaning and healing ointment). The animal recovered well without any sequelae.

First Report of Pratylenchoides leiocauda parasitic on Perilla frutescenes in the Republic of Korea.

Perilla (Perilla frutescens (L.) Britton var. japonica) is an annual herbaceous crop belonging to Lamiaceae. It is one of the most important crops in Korea. A survey of plant parasitic nematodes was carried out in 70 perilla fields in Geumsan and Miryang, Korea in 2020. Migratory endo-parasitic nematodes were extracted from the perilla roots using modified root incubation methods (Mountain and Patrick, 1959). False root-lesion nematodes (Pratylenchoides) were recovered from 41.4% of the fields. They were identified using morphological and molecular analyses. Among the Pratylenchoides species, Pratylenchoides leiocauda was described in France from soil around non-identified grass and weeds. P. leiocauda is reported to weaken the root systems of tomato, potato and strawberry (Sher, 1970; Li et al., 2020). The morphological characteristics of males and females from the 2020 survey were very similar to P. leiocauda. The lateral field contained six incisures and the pharyngeal glands overlapped the intestine dorsally for 1-2 times the body width. Additionally, they had a second nucleus near the pharyngeal intestine valve, female tails with incisures, and a smooth conical tail with 18-23 annules. Measurements and micrographs with the light-microscope (DM5000, Leica, Germany) and camera (DFC450, Leica, Germany) were taken from females (n=23) for mean, standard deviation and range of body length: 824.5 ± 71.0 (657.7-993.8) µm, maximum body width: 28.4 ± 2.7 (24.8-36.2) µm, stylet length: 22.8 ± 0.7 (21.4-24.0) µm and percent of distance from anterior end to vulva / body length: 57.7 ± 1.4 (54.0-60.3). Males (n=5) were characterized by a body length: 653.5 ± 64.3 (555.3-714.7) µm, a stylet length: 20.9 ± 1.0 (19.7-22.0) µm and a spicule length: 26.1 ± 2.5 (22.3-28.5) µm. Morphological measurements and characteristics (Fig. 1A-F) were compared to previous descriptions of P. leiocauda. As a result, the Korean population was larger than that of the originally described population from France, and was more similar to the Chinese population (Sher, 1970; Azizi et al., 2016; Li et al., 2020). In addition, PCR was performed for the COⅠ, LSU rRNA D2-D3 and ITS region using the primers (Mwesige et al., 2020). The sequenced COⅠ, LSU rRNA D2-D3 segments and ITS region are 447, 776 and 777 bp, respectively. The newly obtained sequences were submitted to GenBank database under accession numbers MZ418130, MZ414163 and MZ418133 of ITS region. A BLASTn search of the LSU rRNA D2-D3 sequence was most similar to P. leiocauda (MN539650), which is the species isolated from tomato in China (Li et al., 2020). The identities of these two sequences were 99.9% (775/776), with no insertions/deletions. The phylogenetic relationships strongly support P. leiocauda (Fig. 1G). Symptoms of perilla associated with P. leiocauda under field conditions included small and curled leaves, chlorosis of leaf edges, dark brown root epidermis and root necrosis (Fig. 2A, B). Koch's postulates were completed by inoculating 100 P. leiocauda into ten 45-cm-in-diameter pots filled with sterilized sandy loam soil and planted with perilla cultivar 'Ipdeulkkae 1-ho'. The potted plants were maintained for 50 days at 25℃ under greenhouse conditions. A P. leiocauda reproduction factor was 1.45 ± 0.20 was observed at the end of the trial, with 106 ± 21.6 recovered from soil and 39 ± 6.7 from root tissue. The root and shoot symptoms in the greenhouse trial were the same as those observed under field conditions (Fig. 2C, D). This, therefore, is the first record of P. leiocauda associated with perilla in Korea and management is warranted.

Primer registro de Pharyngodon travassosi (Nematoda, Pharyngodonidae) en Teius teyou (Squamata, Teiidae) en Argentina

First record of Pharyngodon travassosi (Nematoda, Pharyngodonidae) in Teius teyou (Squamata, Teiidae) in the Monte Desert, Argentina We analyzed the gastrointestinal contents of five male specimens of Teius teyou from the Encón locality, San Juan, Argentina to contribute to the understanding of parasites in Teiidae lizards in Argentina. A total of 78 nematodes were found and assigned to the species of Pharyngodon travassosi, with a prevalence of 100 % and mean intensity of 15.6. The diagnostic characteristics of these male Nematodes were: caudal alae enveloping a posterior postcloacal pair of pedunculate papillae, tail filament equal in length to bursa, smooth tail, and eggs with truncated ends. This is the first record of this nematode species for Argentina and the first report of this parasite–host interaction.

Predicting the equity risk premium using the smooth cross-sectional tail risk: The importance of correlation

I provide a new monthly cross-sectional measure of stock market tail risk, SCSTR, defined as the average of the daily cross-sectional tail risk, rather than the tail risk of the pooled daily returns within a month. Through simulations, I find that SCSTR better captures monthly tail risk rather than merely the tail risk on specific days within a month. In an extended period from 1964 until 2018, this difference is important in generating strong in- and out-of-sample predictability and performs better than the historical risk premium and other commonly-used predictors for short- and long-term horizons.

Intraspecific variation in phenotypic and phylogenetic features among Pratylenchus penetrans isolates from Wisconsin, USA.

Pratylenchus penetrans is a common and important agricultural pest in Wisconsin, a USA state with a diverse agriculture. We compared populations from around the state to each other and to data published for populations around the world to gain insight on the variability of features important for identification of this cosmopolitan species. Thirteen isolates from samples collected in soybean fields in ten Wisconsin counties were established in monoxenic cultures. Analysis of morphological features revealed the least variable feature for all isolates collectively was vulva percentage. Features less variable within than among isolates were body width, lip region height, and stylet length. Some isolates showed only the smooth tail tip phenotype and others had a mix of smooth and annulated tail phenotypes. A suite of features provided sufficient pattern to group isolates into four clusters according to hierarchical agglomerative clustering and canonical discriminative analyses, but not with enough distinction to be useful for classification. Haplotype analysis based on the COI mitochondrial gene of the 13 cultured isolates, 39 Wisconsin field populations, and published sequences representing five additional USA states and six countries revealed 21 haplotypes, 15 of which occurred in Wisconsin. Ten haplotypes represented in Wisconsin were shared with populations from Europe, South America, Africa, or Asia. Five haplotypes were unique to Wisconsin, six were unique to The Netherlands, and one was unique to Japan suggesting that even more COI diversity will be revealed when more COI sequences for P. penetrans become available. The maximum pairwise sequence variation was 6% and the SNPs did not alter amino acids, indicating cryptic biodiversity within the species worldwide. The cosmopolitan to localized scale of distribution of COI haplotypes could be due to frequent and ongoing dispersal events, facilitated by life history traits and the broad host range of P. penetrans. Regions of diverse agriculture, like Wisconsin, show promise for studying this important pest and our study confirms the utility of the COI mtDNA gene for studying variation within a species.

First Report of the Root-Lesion Nematode, Pratylenchus alleni, on Soybean in Wisconsin, U.S.A.

HomePlant DiseaseVol. 103, No. 8First Report of the Root-Lesion Nematode, Pratylenchus alleni, on Soybean in Wisconsin, U.S.A. PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of the Root-Lesion Nematode, Pratylenchus alleni, on Soybean in Wisconsin, U.S.A.K. Saikai and A. E. MacGuidwinK. SaikaiUniversity of Wisconsin–Madison, Department of Plant Pathology, Madison, WI 53706Search for more papers by this author and A. E. MacGuidwin†Corresponding author: A. E. MacGuidwin; E-mail Address: aem@plantpath.wisc.eduhttp://orcid.org/0000-0002-4807-8953University of Wisconsin–Madison, Department of Plant Pathology, Madison, WI 53706Search for more papers by this authorAffiliationsAuthors and Affiliations K. Saikai A. E. MacGuidwin † University of Wisconsin–Madison, Department of Plant Pathology, Madison, WI 53706 Published Online:13 Jun 2019https://doi.org/10.1094/PDIS-03-19-0501-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Root-lesion nematodes (Pratylenchus spp.) are economically important nematode pathogens on a wide range of crops. In soybean fields in Wisconsin, it is the most common nematode pest present. In 2013, root-lesion nematodes were detected during routine diagnostics from a soil sample collected in a soybean field in Grant Co., WI. Numerous males were observed, and all life stages appeared smaller than what is typical for Pratylenchus penetrans in Wisconsin. Cultures were established by placing a single adult female in a Petri dish containing ‘IOChief’ sweet corn root explants growing on Gamborg’s B5 medium without auxins or cytokinin. After 3 months, infected root pieces in agar were transferred to new in vitro root cultures on Gamborg’s B5 medium to continue to increase the population. Nematodes were collected for morphological and molecular identification by incubating roots on a Baermann funnel for 48 h. Morphometric data were collected for 25 females and 25 males; measurements are presented as means (range). The body length of females was 482.1 μm (427.8 to 540.6 μm), with a maximum body width of 20.3 μm (18.4 to 22.6 μm). Values of a, b, and c ratios were 23.8 (21.8 to 26.3), 5.1 (4.5 to 6.0), and 20.1 (16.0 to 23.6), respectively. The height of the head was 2.3 μm (1.9 to 2.7 μm), with two lip annules. The stylet length was 14.1 μm (13.4 to 15.1 μm) with anteriorly flattened knobs. The lateral field was marked with four lines at midbody. The vulva percentage was 79% (77 to 81%). Females had a round spermatheca filled with sperm and a postuterine sac with a length of 13.3 μm (8.7 to 19.9 μm) that was slightly shorter than the body width at the vulva. The female tail was subcylindrical or slightly conical with a smooth tail tip and a tail length of 24.2 μm (20.8 to 31.7 μm) with 20 annules (16 to 25). Males were shorter with a body length of 418.0 μm (373.2 to 518.4 μm) and stylet length of 12.6 μm (11.5 to 14.0 μm). The spicules were arched, 16.5 μm long (12.8 to 19.4 μm), and the length of the gubernaculum was 4.0 μm (3.0 to 5.3 μm). The isolate was identified as Pratylenchus alleni based on morphological characters (Castillo and Vovlas 2007; Handoo and Golden 1989). Molecular characterization was based on 18S rDNA (Chizhov et al. 2006), the D2 to D3 expansion region of 28S rDNA (Subbotin et al. 2008), and cytochrome c oxidase subunit I (Derycke et al. 2010) from five specimens. The 28S sequence (GenBank accession no. MK037385) was 99% identical to P. alleni reported in Canada (Dauphinais et al. 2018) with a difference of two nucleotides. The 18S sequence (GenBank accession no. MK035844) was 98% similar to P. scribneri, but the COI sequence (GenBank accession no. MK045330) was only 84% similar to P. scribneri. There were no sequences for either loci for P. alleni available in GenBank. DNA samples of a Canadian isolate of P. alleni obtained from Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu Research and Development Centre (Saint-Jean-sur-Richelieu, Canada) were 99 and 100% identical to the 18S and COI sequences of the Wisconsin isolate, respectively. Therefore, we identified the Wisconsin isolate as P. alleni based on the morphological and molecular data. Three soybean plants of cultivar ‘Corsoy’ were inoculated with 1,000 mixed-stage nematodes of the isolate and grown at 24°C with a 14-h photoperiod in pasteurized loamy sand soil. The reproductive factor (final population density/initial population density) 3 months after inoculation was 3.8, and many lesions were observed on roots. To our knowledge, this is the first report of P. alleni on soybean in Wisconsin. Further investigation about the economic impact of this species to soybean production and its distribution in Wisconsin are planned.The author(s) declare no conflict of interest.

Molecular and morphological characterisation of a new root-lesion nematode, Pratylenchus horti n. sp. (Tylenchomorpha: Pratylenchidae), from Ghent University Botanical Garden

Summary Root-lesion nematodes, Pratylenchus spp., are one of the most important nematode groups in economic terms. The combination of morphological analyses and molecular analyses based on D2-D3 of 28S rDNA, ITS rDNA, and COI mtDNA regions supported the establishment of a new Pratylenchus species, making a total of 103 valid Pratylenchus species. The females of P. horti n. sp. are characterised by the following traits: low labial region with two annuli continuous to the body, en face form belonging to group II sensu Corbett & Clark (1983) with submedian triangular-shaped segments fused with the oral disc and separated from the lateral segments, lateral field with four incisures at vulval level and lacking areolation, robust stylet 15-17 μm long with rounded knobs, and subcylindrical tail with smooth tail tip. The males are largely similar to the females but differ from the females by the partially areolated lateral field, slightly ventrally arcuate and weakly cephalated spicules (15-19 μm), and ventrally curved elongate conical tail with a poorly protruding, crenate bursa. The new species was recovered from soil and root samples from the rhizosphere of Hedychium greenii growing in the Botanical Garden, Ghent University, Belgium.

A comparison of shock–cloud and wind–cloud interactions: effect of increased cloud density contrast on cloud evolution

The similarities, or otherwise, of a shock or wind interacting with a cloud of density contras t$ \chi = 10$ were explored in a previous paper. Here, we investigate such interactions with clouds of higher density contrast. We compare the adiabatic hydrodynamic interaction of a Mach 10 shock with a spherical cloud of $\chi = 10^{3}$ with that of a cloud embedded in a wind with identical parameters to the post-shock flow. We find that initially there are only minor morphological differences between the shock-cloud and wind-cloud interactions, compared to when $\chi = 10$. However, once the transmitted shock exits the cloud, the development of a turbulent wake and fragmentation of the cloud differs between the two simulations. On increasing the wind Mach number, we note the development of a thin, smooth tail of cloud material, which is then disrupted by the fragmentation of the cloud core and subsequent `mass-loading' of the flow. We find that the normalized cloud mixing time ($t_{mix}$) is shorter at higher $\chi$. However, a strong Mach number dependence on tmix and the normalized cloud drag time, $t'_{drag}$, is not observed. Mach-number-dependent values of $t_{mix}$ and $t'_{drag}$ from comparable shock-cloud interactions converge towards the Mach-number-independent time-scales of the wind-cloud simulations. We find that high $\chi$ clouds can be accelerated up to 80-90 per cent of the wind velocity and travel large distances before being significantly mixed. However, complete mixing is not achieved in our simulations and at late times the flow remains perturbed.

Observations on Malenchus geraerti n. sp. (Rhabditida: Tylenchidae), a morphological and molecular phylogenetic study.

Malenchus geraerti n. sp., recovered from natural regions of northern Iran, is described and illustrated based on morphological, morphometric and molecular data. The new species is characterized by having females with a short body, an anteriorly wide S-shaped amphidial opening narrowing posteriorly, cuticle with prominent annuli, lateral field a plain band with smooth margins, muscular metacorpus with well-developed valve and corresponding plates, spermatheca filled with small spheroid sperm cells, vulva sunken in body with large epiptygma and no flap, and conical tail tapering gradually to a more or less pointed tip. Males of the new species are characterized by having a short body, tylenchoid spicules, adcloacal bursa with smooth margin and tail similar to that of the female. Morphologically, the new species is similar to five known species of the genus: M. fusiformis, M. machadoi, M. pachycephalus, M. solovjovae and M. undulatus. It most closely resembles M. pachycephalus, but as a cryptic species it can be differentiated using morphological and molecular characteristics. Comparisons with the four other aforementioned species are also discussed. Molecular phylogenetic studies using partial sequences of small and large subunit ribosomal DNA fragments reveal that the new species forms a clade with the species M. neosulcus in the small subunit (SSU) rDNA, and two species of Lelenchus in the large subunit (LSU) rDNA tree.

Singular behavior of jet substructure observables

Jet substructure observables play a central role at the Large Hadron Collider for identifying the boosted hadronic decay products of electroweak scale resonances. The complete description of these observables requires understanding both the limit in which hard substructure is resolved, as well as the limit of a jet with a single hard core. In this paper we study in detail the perturbative structure of two prominent jet substructure observables, $N$-subjettiness and the energy correlation functions, as measured on background QCD jets. In particular, we focus on the distinction between the limits in which two-prong structure is resolved or unresolved. Depending on the choice of subjet axes, we demonstrate that at fixed order, $N$-subjettiness can manifest myriad behaviors in the unresolved region: smooth tails, end-point singularities, or singularities in the physical region. The energy correlation functions, by contrast, only have non-singular perturbative tails extending to the end point. We discuss the effect of hadronization on the various observables with Monte Carlo simulation and demonstrate that the modeling of these effects with non-perturbative shape functions is highly dependent on the $N$-subjettiness axes definitions. Our study illustrates those regions of phase space that must be controlled for high-precision jet substructure calculations, and emphasizes how such calculations can be facilitated by designing substructure observables with simple singular structures.

Complete mitochondrial genomes of the smooth tail nine-spined sticklebacks Pungitius laevis (Gasterosteiformes, Gasterosteidae)

The complete mitochondrial genome sequences of three divergent lineages of the smooth tail nine-spined stickleback (Pungitius laevis) were obtained with massive parallel sequencing of their genomic DNA. The genome sequences were 16 574–16 580 bp long, and the gene order and contents were identical to those of other sequenced Pungitius mitogenomes. Although the mitogenome sequences of all three P. laevis lineages clustered within the genus Pungitius, they were clearly distinct and showed divergence comparable to that seen between some Pungitius species.

Multi-temperature fluid-dynamic model equations from kinetic theory in a reactive gas: The steady shock problem

Starting from a simple kinetic model for a chemical reaction, multi-temperature reactive Euler equations are derived for physical regimes in which evolution is driven by elastic collisions within the same species and mechanical relaxation is faster than the thermal one. The achieved hydrodynamic equations, where all inhomogeneous exchange rates take analytical closed form for simple collision models, are then used for the analysis of the steady shock problem. Results indicate that smooth shock profiles occurring for slightly supersonic flows bifurcate to weak solutions (jump discontinuity followed by a smooth tail) for increasing Mach number.

Resonance-induced multimodal body-size distributions in ecosystems

The size of an organism reflects its metabolic rate, growth rate, mortality, and other important characteristics; therefore, the distribution of body size is a major determinant of ecosystem structure and function. Body-size distributions often are multimodal, with several peaks of abundant sizes, and previous studies suggest that this is the outcome of niche separation: species from distinct peaks avoid competition by consuming different resources, which results in selection of different sizes in each niche. However, this cannot explain many ecosystems with several peaks competing over the same niche. Here, we suggest an alternative, generic mechanism underlying multimodal size distributions, by showing that the size-dependent tradeoff between reproduction and resource utilization entails an inherent resonance that may induce multiple peaks, all competing over the same niche. Our theory is well fitted to empirical data in various ecosystems, in which both model and measurements show a multimodal, periodically peaked distribution at larger sizes, followed by a smooth tail at smaller sizes. Moreover, we show a universal pattern of size distributions, manifested in the collapse of data from ecosystems of different scales: phytoplankton in a lake, metazoans in a stream, and arthropods in forests. The demonstrated resonance mechanism is generic, suggesting that multimodal distributions of numerous ecological characters emerge from the interplay between local competition and global migration.

GRB980923. A BURST WITH A SHORT DURATION HIGH-ENERGY COMPONENT

The prompt emission of Gamma Ray Bursts (GRBs) is usually well described by the Band function: two power-laws joined smoothly at a given break energy. In addition to the Band component, a few bursts (GRB941017, GRB090510, GRB090902B and GRB090926A) show clear evidence for a distinct high-energy spectral component, which in some cases evolves independently from the prompt keV component and is well described by a power-law (PL), sometimes with a cut-off energy; this component is found to have long duration, even longer than the burst itself for all the four bursts. Here we report the observation of an anomalous short duration high energy component in GRB980923. GRB980923 is one of the brightest Gamma-Ray Bursts (GRBs) observed by BATSE. Its light curve is characterized by a rapid variability phase lasting ~ 40 s, followed by a smooth emission tail lasting ~ 400 s. A detailed joint analysis of BATSE (LAD and SD) and EGRET TASC data of GRB980923 reveles the presence of an anomalous keV to MeV component in the spectrum that evolves independently from the prompt keV one. This component is well described by a PL with a spectral index of -1.44 and lasts only ~ 2 s; it represents one of the three clearly separated spectral components identified in GRB980923, the other two being the keV prompt emission, well described by the Band function and the tail, well fit by a Smoothly Broken Power Law (SBPL).

First Report of the Lesion Nematode, Pratylenchus agilis, Parasitizing Wheat in China

Wheat (Triticum aestivum L.) fields in Zhengzhou, Henan Province that exhibited reduced height and number of tillers were surveyed in 2008, and samples were collected for analyses. Fifteen of thirty-five samples contained a nematode suspected of causing small, brown lesions in roots. Both lateral roots and root hairs were reduced in infected plants. Nematode presence was associated with enlarging lesions and necrotic roots. We also observed lesion nematode infestation in samples with no symptoms in the roots. During the growing season, wheat yield increased by 14% with nematocide treatments in Zhengzhou suburb fields. The morphological and molecular analyses of the nematodes isolated from soil samples established the identity of the species as the lesion nematode, Pratylenchus agilis (2,3). Morphological characteristics that were used for identification included female body, lip annules, tail terminus, number of lines in the lateral field, stylet knobs, stylet length, and vulva location in relation to body length. Females were cylindrical, measured 452 to 811 μm long, and contained two lip annules, a smooth tail terminus, four lateral lines, a vulva at 72.64 to 79.97%, a stylet of 16.20 to 17.55 μm, basal esophageal lobes elongated less than twice the body width, and stylet knobs rounded posteriorly. Males were rare and the spermatheca was empty. Molecular analysis was conducted by amplifying the internal transcribed spacer (ITS) regions ITS1 and 2. Sequence of ITS regions from this population (GenBank Accession No. JQ039330) showed highest sequence homology to P. agilis isolate PagKL5 (GenBank Accession No. FJ71289.1) with the identity of 90%. High variability at species level has been found for Pratylenchus species (1). On the basis of the morphological traits and molecular analyses, the nematodes were identified as P. agilis. To our knowledge, this is the first report of P. agilis parasitizing wheat.

Internal Structure of Planar Electrochemical Doping Fronts in Organic Semiconductors

The internal structure of electrochemical doping fronts in organic semiconductors is investigated using an extended drift-diffusion model for ions, electrons, and holes. The model also involves the injection barriers for electrons and holes in the partially doped regions in the form of the Nernst equation, together with a strong dependence of the electron and hole mobility on concentrations. It is shown that the internal structure of the doping fronts is controlled by a balance between the diffusion and mobility processes. The asymptotic behavior of the concentrations and the electric field is studied analytically inside the doping fronts. The numerical solution for the front structure confirms the most important findings of the analytical theory: a sharp head of the front in the undoped region, a smooth relaxation tail in the doped region, and a plateau at the critical point of transition from doped to undoped regions. The theoretically predicted complex structure of the doping fronts is in agreement with the previous experimental data. The acceleration of the p- and n-fronts toward each other in light-emitting electrochemical cells is described. The theoretical predictions for the planar front acceleration are in a good quantitative agreement with the experimental measurements for the backside of the curved doping fronts.

Metabolites of the Radiosensitizer Nicotinamide Are Unlikely to Contribute to the Degree of Emesis Observed With the Parent Drug

Nicotinamide is a potent radiosensitizer currently employed in the treatment of cancer of the bladder, head, and neck. Unfortunately, nicotinamide is also a potent emetic at the concentrations required for radiosensitization. Previously, we have demonstrated that nicotinamide-induced emesis is the direct result of decreased spontaneous peristaltic activity in the ileum. However, the effect of nicotinamide's metabolites on peristaltic activity have not been investigated, although several studies have unsuccessfully attempted to correlate the degree of emesis with the levels of the metabolites in plasma. Isolated rat ileum rings and rat tail arteries were perfused with oxygenated Krebs solution in an organ bath. Nicotinamide, 1-methynicotinamide, or N-oxide nicotinamide were introduced to the perfusate and changes in amplitude of spontaneous peristaltic activity or phenylephrine-induced vasoconstriction recorded. Nicotinamide inhibited peristalsis in the ileum and agonist-induced vasoconstriction in the rat tail arteries, as previously observed. However, the primary metabolites of nicotinamide were without effect. Gut smooth muscle and rat tail artery are sensitive to the relaxant effects of nicotinamide. The primary metabolites of nicotinamide are not vasoactive and do not blunt either spontaneous or agonist-induced contraction and are thus unlikely to contribute to the degree of emesis observed following nicotinamide administration.

A Comprehensive Analysis ofSwiftXRT Data. I. Apparent Spectral Evolution of Gamma‐Ray Burst X‐Ray Tails

An early steep decay component following the prompt GRBs is commonly observed in Swift XRT light curves, which is regarded as the tail emission of the prompt gamma rays. Prompted by the observed strong spectral evolution in the tails of GRBs 060218 and 060614, we present a systematic time-resolved spectral analysis for the Swift GRB tails detected between 2005 February and 2007 January. We select a sample of 44 tails that are bright enough to perform time-resolved spectral analyses. Among them 11 tails are smooth and without superimposing significant flares, and their spectra have no significant temporal evolution. We suggest that these tails are dominated by the curvature effect of the prompt gamma rays due to delay of propagation of photons from large angles with respect to the line of sight. More interestingly, 33 tails show clear hard-to-soft spectral evolution, with 16 of them being smooth tails directly following the prompt GRBs, and the others being superimposed with large flares. We focus on the 16 clean, smooth tails and consider three toy models to interpret the spectral evolution. The curvature effect of a structured jet and a model invoking superposition of the curvature effect tail and a putative underlying soft emission component cannot explain all the data. The third model, which invokes an evolving exponential spectrum, seems to reproduce both the light curve and the spectral evolution of all the bursts, including GRBs 060218 and 060614. More detailed physical models are called for to understand the apparent evolution effect.

Smooth and Starburst Tidal Tails in the GEMS and GOODS Fields

GEMS and GOODS fields were examined to z~1.4 for galaxy interactions and mergers. The basic morphologies are familiar: antennae with long tidal tails, tidal dwarfs, and merged cores; M51-type galaxies with disk spirals and tidal arm companions; early-type galaxies with diffuse plumes; equal-mass grazing-collisions; and thick J-shaped tails beaded with star formation and double cores. One type is not common locally and is apparently a loose assemblage of smaller galaxies. Photometric measurements were made of the tails and clumps, and physical sizes were determined assuming photometric redshifts. Antennae tails are a factor of ~3 smaller in GEMS and GOODS systems compared to local antennae; their disks are a factor of ~2 smaller than locally. Collisions among early type galaxies generally show no fine structure in their tails, indicating that stellar debris is usually not unstable. One exception has a 5x10**9 Msun smooth red clump that could be a pure stellar condensation. Most tidal dwarfs are blue and probably form by gravitational instabilities in the gas. One tidal dwarf looks like it existed previously and was incorporated into the arm tip by tidal forces. The star-forming regions in tidal arms are 10 to 1000 times more massive than star complexes in local galaxies, although their separations are about the same. If they all form by gravitational instabilities, then the gaseous velocity dispersions in interacting galaxies have to be larger than in local galaxies by a factor of ~5 or more; the gas column densities have to be larger by the square of this factor.