Wide Ring Research Articles

Comparison of Insulin-Induced Digital Vessel Ring Responses of Laminitic and Clinically Healthy Horses

Hyperinsulinemia leads to insulin resistance of blood vessels and interferes with circulation of laminae of the equine foot. The objective of the study was to compare the digital vessel responses of clinically healthy and laminitic horses with and without experimental induction of insulin resistance. Vessel segments (artery and vein) collected after euthanasia were cut into 3-mm wide rings and were prepared in tissue baths containing Tyrode solution for response studies. Two rings of each vessel type from each horse were used as nonresistant, and two were made insulin resistant. Insulin resistance was induced by incubating the rings with 10-μM bath concentration of insulin. Then, all rings were contracted with phenylephrine (5 μM). When the contraction reached a plateau, insulin (10 μM) was added, and the response monitored for 30 minutes. The response to insulin was calculated as a percentage of the phenylephrine response. The results showed that the responses of the nonresistant rings differed significantly between the groups. However, when all rings were made insulin resistant, the significance between the groups disappeared. In the laminitic group, responses of resistant and nonresistant rings did not differ, whereas in the healthy group, the vessel responses differed significantly. In all experiments, arterial and venous rings followed the same pattern, but the magnitudes were greater in arterial rings. The findings suggest that the vessel responses to insulin are altered in laminitis which could be due to insulin resistance.

Effect of morphology on spectral properties of magneto-trion X+ in vertically coupled type II quantum dots

The energy spectrum of a positively charged exciton confined in vertically coupled type II quantum dots with different morphologies in the presence of the external magnetic field is studied. The effect of the quantum dot morphology on the curves of the lowest energy levels as functions of the magnetic field is analyzed. It is shown that a strong correlation presented in this system generates the Aharonov–Bohm oscillations of the lower energy levels similar to those in wide quantum ring. The novel curves of the trion energies dependences on the external magnetic field for the disk-like, lens-like, and cone-like structures are presented.

In vitro responses of insulin resistant and nonresistant digital vessels of healthy and laminitic horses (851.11)

Hyperinsulinemia leads to insulin resistance of blood vessels and interferes with circulation of lamina of the equine foot. The objective of the study was to compare the digital vessel responses of clinically healthy and laminitic horses with and without experimental induction of insulin resistance. Vessel segments (artery and vein) collected after euthanasia, were cut into 3 mm wide rings and were prepared in tissue baths containing Tyrode’s solution for response studies. Two rings from each horse were used as non‐resistant and two were made insulin‐resistant. All rings were contracted with phenylephrine (10‐6.5M). When the contraction reached a plateau, insulin (10‐5M) was added and the response monitored. The response to insulin was calculated as a percentage of the phenylephrine response. The results showed that the responses of the non‐resistant rings differed significantly between the groups. However, when all rings were made insulin‐resistant, the significance between the groups disappeared. In the laminitic group, responses of resistant and non‐resistant rings did not differ, whereas in the healthy group, the vessel responses differed significantly. In all experiments, arterial and venous rings followed the same pattern but the magnitudes were greater in arterial rings. The findings suggest that the vessel responses to insulin are altered in laminitis which could be due to insulin resistance.Grant Funding Source: Supported by Equine Health Studies Program of LSU‐SVM

AN ANALYTICAL STUDY ON TEST STANDARDS FOR ASSESSMENT OF JUTE GEOTEXTILES FOR GLOBAL ACCEPTANCE

Geosynthetics made of man-made fibres, and used fo r addressing a host of geotechnical problems, have for the last two decades, registered a remarkable growth clinching about 95% share of the total global demand in several fields such as erosion control, management of slopes, strengthening of roads, stabi lization of embankments, protection of river banks, consolidation of soft soils etc. One such major application of Geosynthetic material is in the field of road construction which has bec ome an established phenomenon worldwide. Recently, however, increasing environmental concerns concomitant with the alarmi ng danger of carbon footprint generation have generated interest in and led to acceptance of natural Jute Geotextile (JGT) whe re this material plays a significant role for the purpose of reinforcement p roviding dimensional stability as well as cushionin g effect to the road surface thereby improving the life cycle as well as mainten ance cost of the road. With the increasing use of J ute Geotextile worldwide in combating geotechnical problems without hampering e nvironmental sustainability, and the confidence wit h which they are being used is also developing amongst engineers, manufacturers and end users is opening new avenues for potential Jute Geotextile . Hence, there is a dire need for quality control in terms o f testing and evaluation of Jute Geotextile demandi ng formulation of new standards for testing. The existing test standards for synthe tic Geotextiles for evaluating different end use pr operty parameters are not uniform globally i.e., these test standards vary from count ry to country. However, in the field of standardiza tion for testing of different properties of Jute Geotextiles there is a paucity o f data for formulation of specifications and qualit y control guidelines. Test standards for synthetic Geotextiles understandably do not exa ctly apply to JGT. While study is on to develop exc lusive test and design standard for JGT, there is need to adopt any of the existing standards for synthetic Geotextiles that cater to the majority of requirements in the interim period. The paper suggests adoption of ASTM standards for testing JGT because of the wide rang e of test standards available and their credibility.

Response to climate changes in radial growth of Picea crassifolia in the Qilian mountains of northwestern China

In order to investigate the response to climate changes in radial growth of Picea crassifolia at the lower tree line in the middle Qilian mountains in northwestern China, relationships of standardized chronologies of annual ring, earlywood and latewood widths with mean monthly temperature and total monthly precipitation were analyzed by ways of correlation and pointer year analyses. The results show that annual ring, earlywood and latewood widths are significantly negatively correlated with mean monthly temperature in June and July. Annual ring and earlywood widths are significantly and positively correlated with total monthly precipitation in March, May and June and negatively correlated with total monthly precipitation in September. Latewood width is less sensitive to climate changes than the width of earlywood and insignificantly sensitive to precipitation. The results of pointer year analysis revealed that when summer temperatures are higher than the mean summer temperature synchronization and the summer precipitation lower than mean summer precipitation synchronization, narrow annual rings are formed. Wide annual rings are formed when summer temperatures are lower than the mean summer temperature synchronization and summer precipitation higher than mean summer precipitation synchronization. The results indicate that more precipitation in the spring and summer is helpful for radial growth while warmer summer restricts radial growth of P. crassifolia at the lower tree line in the middle Qilian mountains.

Lead (II)-Selective Polymeric Electrode Using PVC Membrane Based on a Schiff Base Complex of 1,2- Bis(Salicylidin Aminooxy) Ethane As an Ionophore

A PVC membrane electrode for lead ion based on 1,2- bis(salicylidin aminooxy) ethane as a neutral carrier was prepared. The electrode exhibits a near Nernstion response (26/49±0/7 mv/decade) for lead ion over a relatively wide concentration rang (1/0×10 -6 to 1/0×10 -1 ) with a limit detection 7/6×10-7M. It has a releatively fast reasponse time (<10 s). The proposed membrane electrode revealed very good selectivity in the PH= 4-7. The influence of membrane composition enthe electrode response was studied. The proposed electrode was used for the determination of lead ion in wastewater, water and wastewater of manufactory.

Four new species ofDesmodora(Nematoda) from the deep south-east Atlantic, and a case of intersexuality in Desmodoridae

Four new species of the genusDesmodoraare described from the South Atlantic off the south-eastern coast of the State of Rio de Janeiro, Brazil.Desmodora porosumsp. nov. is characterized by sexual dimorphism in the shape of the amphids, which are closed loop-shaped in males, and multispiral amphids in females. A case of intersexuality was found in the species, with a functional female gonad.Desmodora profundumsp. nov. is characterized by filiform spicules with a capitulum, buccal cavity with one dorsal and one small ventral tooth, tail cylindrical with a terminal spinneret, and wider rings in the neck region than on the rest of the body.Desmodora veronicaesp. nov. possesses cryptospiral amphids, a buccal cavity with one dorsal tooth and two smaller ventral teeth, 14 tubular pre-cloacal supplements, two ventral cuticular protruberances on the tail, and curved spicules with a capitulum and velum.Desmodora curvatumsp. nov. has the cuticle finely striated, without somatic setae, multispiral amphids, and a gubernaculum without apophysis, curved dorsally with the tip directed toward the end of the body.

Distribution of sulphur and magnesium in the red coral

The concentrations of major and trace elements were measured in red coral skeletons (Corallium rubrum) by electron microprobe (EMP), isotope dilution inductively coupled mass spectrometry (ID-ICPMS) and laser ablation-ICPMS (LA-ICPMS). The average composition (in mg/kg or ppm) is as follows: Ca: 356300±3200, Mg: 29500±2400, Sr: 2600±250, S: 3100±400, Na: 4200±500, K: 140±20, P: 140±40, B: 28±4, Ba: 9±1, Fe: 8±3, Li: 4±1, Mn: 1±0.5, Pb: 0.5±0.3, U: 0.08±0.05. In terms of Mg, the compositions of the red coral skeletons range from 9 to 15mol% MgCO3 with a mean value of 12±1%. Concentrations of sulphur are high (approx. 3000ppm) and among the highest reported in biogenic calcites. EMP maps (Mg and S) and organic matter (OM) staining show a regular alternation of 100–200μm wide annual growth rings. Combination of these results with a previous study (Marschal et al., 2004) suggests that Mg-rich rings form during the period spring to early fall, while S-rich rings form immediately after (late autumn and winter). Elemental mapping by EMP shows an unexpected anticorrelation between S and Mg confirmed by LA-ICPMS. This anticorrelation is ascribed to the concomitant presence of S in the organic matter and the anticorrelation between Mg and OM in the skeleton. However, mass balance constraints indicate that in the skeleton sulphur is probably present both as organo-sulphur and structurally substituted sulphur. The studied samples of red coral were collected at various locations and different depths (8–73m) where the temperature of the sea water was monitored for long periods of time. Although overall decreases of the Mg/Ca and Sr/Ca are observed as a function of depth (and temperature), the use of these ratios as an indication of the sea water temperature (SWT) seems difficult. In addition, a single colony that grew in an area where the temperature was monitored for 30years did not register the measured increase of SWT of about 1°C. However, Mg and OM distributions inside skeletons could be good indicators of variations of growth rates on decadal time scales and anomalous ‘summer suffering’ events that could be associated with periods of unusually high SWT conditions. The red coral is thus an example of how growth dynamics (and not temperature alone) affects the chemistry of biominerals.

Temperature‐induced responses of xylem structure of Larix sibirica (Pinaceae) from the Russian Altay

Xylem structure determines the hydraulic and mechanical properties of a stem, and its plasticity is fundamental for maintaining tree performance under changing conditions. Unveiling the mechanism and the range of xylem adjustment is thus necessary to anticipate climate change impacts on vegetation. To understand the mechanistic process and the functional impact of xylem responses to warming in a cold-limited environment, we investigated the relationship between temperature and tracheid anatomy along a 312-yr tree-ring chronology of Larix sibirica trees from the Altay Mountains in Russia. Climate-growth analyses indicated that warming favors wider earlywood cell lumen, thicker latewood walls, denser maximum latewood, and wider rings. The temperature signal of the latewood was stronger (r > 0.7) and covered a longer and more stable period (from June to August) than that of earlywood and tree-ring width. Long-term analyses indicated a diverging trend between lumen and cell wall of early- and latewood. Xylem anatomy appears to respond to warming temperatures. A warmer early-growing season raises water conduction capacity by increasing the number and size of earlywood tracheids. The higher-performing earlywood tracheids promote more carbon fixation of the latewood cells by incrementing the rate of assimilation when summer conditions are favorable for growth. The diverging long-term variation of lumen and cell wall in earlywood vs. latewood suggests that xylem adjustments in latewood increase mechanical integrity and support increasing tree size under the ameliorated growing conditions.

Climatic signal in tree-ring chronologies of Cedrus deodara from Chitral Hindukush Range of Pakistan

Tree-rings are an important tool for the investigation of paleoclimatic records for regions or periods of time with no instrumental climatic data. However, the responses of different species and sites to various climatic parameters are unusual. In the present study, we developed tree-ring-width chronologies of Cedrus deodara from three different sites of Chitral Hindukush range of Pakistan. The study was conducted to understand tree-growth climate relationship and its applicability in proxy climate investigations. The chronologies covered the past 469 to 595 years, with a mean segment length (MSL) ranging from 148 to 223 years. Climatic data obtained from the three weather stations showed strong correlation and was found useful for tree-ring climate relationships. Correlation Function (CF) and Response Function (RF) analysis showed that spring precipitation (March–May) is a critical limiting factor for tree-ring growth, and temperature prior to November may also play a major role in affecting tree ring-growth. The results exposed that the three sites have continuous relationship indicated that only single species from different locations are affected by the same environmental variables and hence can be used in climate reconstruction in combination. The Cedrus deodara chronologies developed at different locations had several corresponding narrow and wide marker rings indicating a large macroclimatic response to regional climatic conditions. The current study suggests that the tree-rings of Cedrus deodara from the Chitral Hindukush range could be used to develop chronologies for the reconstruction of seasonal climatic variables.

Power quality problems and solutions

This paper addresses the power quality problems and solutions related to (i) wind power generation and (ii) large industrial customers. Intermittent nature of wind power affects the quality of its electrical power output. The usage of low cost energy saving equipments also generates harmonics and voltage flicker thus affects the quality of supply voltage. A wide rang of solutions are being already proposed with the development on power electronic devices and electrical machines. This paper is organized to discuss the (i) power quality problems in brief, (ii) four major developments in wind generator technologies and (iii) solutions to large industrial customers using Dynamic Voltage Restorer (DVR), Active Power Filter (APF) and Static Compensator (STATCOM). Finally development in power electronic devices' control is briefed in each of the devices, which has utilizes these power electronic devices with integrated solutions to solve number of power quality problems.

Development and evaluation of a two-level functional structure for the thin film encapsulation

This paper reports a two level capping structure for encapsulating micro-electro-mechanical system (MEMS) devices. The two level capping solves the main issue of the longer release time as well as safe sealing in thin film encapsulation (TFE). In this technique, the first cap layer has many etch holes, which were uniformly distributed on it to enhance the removal of the sacrificial layer. The second cap layer forms a cap on every etch hole in the first cap layer to protect the mass loading on MEMS devices. This technique was found to be very effective in reducing the release time of the TFE. For the 1200 µm × 1200 µm sized cavity encapsulation, this technique decreases the release time of the TFE by a factor of 24 in comparison to the sidewall located channel scheme. The presented technique also helps in reducing the size of TFE as the etch holes are uniformly distributed on the TFE itself. Wide seal rings were not required to accommodate sidewall channels.

Computational fluid dynamics study of the optimal design and operating conditions of the segmentation ring used in parallel segmented flow columns

We report on a numerical study wherein we modeled the influence of the segmentation ring used in the recently introduced parallel segmented flow concept. The study reconfirms that the parallel segmented flow concept can indeed improve separation performance of radially heterogeneous beds. It was however also found that the segmentation ring in itself introduces significant flow disturbances. Depending on its thickness and the fraction of the total flow rate going through the central opening, the ring itself can constitute a loss in volumetric variance (σv2) in the order of a few up to a few tens of μl2. Although the ideal flow-split ring would be infinitely thin, it was found that halving the current 0.62mm ring thickness used in literature to 0.31mm would already eliminate most of its negative effect. At the inlet, the optimal central flow rate fraction for a 0.62mm as well as a 0.31mm wide ring in a 4.6mm I.D. column lies in the range of 0.25–0.4. At the outlet, the optimal range is 0.15–0.4.

Effect of Pentoxifylline and Losartan on insulin resistant equine digital vessels

Insulin response on normal blood vessel is a relaxation. However, insulin produces contraction in insulin‐resistant (IR) vessels. IR has been associated with equine laminitis. The objective of this study was to evaluate the effectiveness of two potential drugs (Losartan &amp; Pentoxifylline) to counteract the responses of experimentally induced‐insulin resistant equine digital vessels to insulin in vitro. Palmar digital arteries and veins (2″ long) were collected from lean horses (overnight fasting plasma insulin 65pmol/L and glucose 5.614mmol/L) immediately after euthanasia. Eight 3‐mm wide rings were cut (4 arterial and 4 venous) and were set in in‐vitro tissue baths for response studies. Two rings from each vessel type were made IR by incubating them with insulin at a concentration of 10−5M for 30 min. The other rings were used as control. Then all these rings were contracted with phenylephrine 10−6.5M and when it reached a plateau either losartan (10−5M) or pentoxifylline (10−5M) was added to both insulin resistant and non resistant (control) rings and allowed to stay in the bath for 5 minutes, before a single dose of insulin (10−5M) was added to all rings. The response to insulin was monitored for another 30 minutes. Losartan pre‐treatment of IR vessels produced contraction to insulin. On the contrary, pentoxifylline caused relaxation suggesting it could be beneficial in the treatment of equine laminitis. The study was supported by USDA 1433 Formula ‐ LSU‐SVM.

Small particles in Pluto's environment: effects of the solar radiation pressure

Impacts of micrometeoroids on the surfaces of the plutonian small satellites Nix and Hydra can generate dust particles. Even in this region so far from the Sun these tiny ejected particles are under the effects of the solar radiation pressure. In this work, we investigate the orbital evolution of the escaping ejecta from both the small satellites under the effects of the radiation pressure combined with the gravitational effects of Pluto, Charon, Nix and Hydra. The mass production rate of micron-sized dust particles generated by micrometeoroids hitting the satellites is obtained, and numerical simulations are performed to derive the lifetime of the ejecta. These pieces of information allow us to estimate the optical depth of a putative ring, which extends from the orbits of Nix to Hydra. The ejected particles, between the orbits of Nix and Hydra, form a wide ring of about 16 000 km. Collisions with the massive bodies and escape from the system are mainly determined by the effects of the solar radiation pressure. This is an important loss mechanism, removing 30 per cent of the initial set of 1 μm-sized particles in 1 yr. The surviving particles form a ring too faint to be detectable with the derived maximum optical depth of 4 × 10 −11 .

Design of VCO with a Differential Tunable Active Inductor

This paper presents a wide tuning rang CMOS voltage control oscillator (VCO) suitable for radio frequency operation. The oscillator based upon the classic LC-tuned negative-resistance topology, with a novel low voltage, high performance active inductor. In the proposed circuits' structure, the coarse frequency tuning is provided by the tunable active inductor, while the fine tuning is controlled by varactor. Using a 0.18µm CMOS process, complete pattern VCOs are designed in ADS. The output frequency is 5.5GHz. The measured phase noise in 1-MHz offset is -81dBc. The non existence of passive components causes VCO to have the smaller chip area than the circuit with passive inductors.

A 23-GHZ BANDWIDTH AUTOMATIC GAIN CONTROL AMPLIFIER WITH WIDE DYNAMIC RANGE FOR HIGH SPEED COMMUNICATION

In this paper, a wide bandwidth and wide dynamic range AGC amplifler is presented. A push-pull variable gain amplifler (VGA) structure is proposed for wide dynamic rang. Moreover, the bandwidth enhancement technique is used in the post amplifler design to ensure the wide bandwidth and gain of whole circuit. The experimental results demonstrate that the proposed AGC amplifler fabricated in 0.13m SiGe BiCMOS process, achieves a 23-GHz bandwidth and 36-dB dynamic rang whereas the power and area consumption are 57.6mW and 1.9mm 2 , respectively.

Gain Coefficient Calculation for Short Wave Laser Emission from Sodium like Co

Level structure, oscillator strengths, transition probabilities and radiative life times are evaluated for 1s2 2s2 2p63l, 4l, 5l (l = 0, 1, 2, 3, 4) states in sodium like Co16+. The calculations are carried out using COWAN code. The calculations made were compared with other results in literature where a good agreement is found. We also report on some unpublished energy values and oscillator strengths. Our results are used in the calculation of reduced population of 21 fine structure levels over a wide rang of electron density values (1018 to 1020) at various electron plasma temperature. For those transitions with positive population inversion factor, the gain coefficients are evaluated and plotted against the electron density.

Modeling and Simulation Multi Motors Web Winding System

Web winding systems allow the operations of unwinding and rewinding of various products including plastic films, sheets of paper, sheets, and fabrics. These operations are necessary for the development and the treatment of these products. Web winding systems generally consist of the same machine elements in spite of the diversity of the transported products. Due to the wide rang variation of the radius and inertia of the rollers the system dynamic change considerably during the winding/ unwinding process. Decentralized PI controller for web tension control and linear speed control are presented in this paper. The PI control method can be applied easily and is widely known, it has an important place in control applications. Simulation results show the effectiveness of the proposed linear speed and tension controller for web winding multi motors systems.

Ikona Bogorodice s Djetetom iz crkve Sv. Nikole na Prijekom u Dubrovniku

Ikona Bogorodice s Djetetom iz crkve sv. Nikole na Prijekom u Dubrovniku, nakon provedenog konzervatorsko-restauratorskog zahvata, na temelju stilske analize povezuje se s poznatom „Bogorodicom benediktinki“ iz Zadra i datira u isto vrijeme oko 1300. godine. Analizira se ikonografija ikone te otvara problem utjecaja slikarstva istočnog Mediterana na slikarstvo Dalmacije u XIII. stoljeću.