Multiple records and polymorphism of Parastichopus regalis (Cuvier, 1817) (Echinodermata: Holothuroidea: Stichopodidae) along the Algerian coast

The family Stichopodidae is represented in the Mediterranean Sea by the genus Parastichopus which includes two non-endemic species; Parastichopus tremulus (Gunnerus, 1767) and Parastichopus regalis (Cuvier, 1817). On the Algerian coast (southwestern Mediterranean Sea), two morphotypes of P. regalis were observed, one with dark spots on the dorsal surface and the other non-spotted. In total, 65 individuals of P. regalis were recorded from 22 stations along the Algerian coast during an oceanographic campaign. Twelve individuals (6 of each morphotype) were used for a comparative study of the morphological (including endoskeletal) characteristics. Table ossicles, the only ossicles of the body wall of the two morphotypes of P. regalis, are here compared with regard to the disk diameter of the tables and the total area of the surface of the disc. Statistical analysis did not show any significant differences between the spotted and the non-spotted morphotypes.

Potential phenotypic plasticity within Simulium nigrimanum Macquart, 1838 (Diptera: Simuliidae) larvae

Black fly larvae (Diptera: Simuliidae) are suspension filter-feeders which strongly depend on water velocity for proper feeding. Black fly species feature different microhabitat preferences. Studies of Holarctic black fly larvae revealed their phenotypic plasticity in response to water current velocity variation, but such studies have been rarely undertaken with Neotropical black flies. The current work presents results on the phenotypic plasticity of the black fly species Simulium nigrimanum Macquart. Twelve last instar larvae, sampled from the Brazilian Cerrado, were photographed under a stereoscopic microscope and measured using the CMEIAS Image tool software. Linear regressions with water velocity as the independent variable were performed, indicating that while body size and anal disk diameter correlated positively with water velocity, labral fan length correlated negatively. The observed relationships between water velocity and labral fan length and anal disk diameter were consistent with the literature, while the pattern of body size variation partially corroborated previous studies. The present work results suggest that potential phenotypic plasticity can be observed in black fly larvae within one population distributed in different microhabitats of the same stream section, as opposed toprevious reports implying that such variation is only found among population from different streams.

DESCRIPTION OF THE PARAMETERS OF THE ELLIPSE NEEDLE DISC OF THE SOIL PROCESSING TOOL

Due to the well-known advantages, rotary tillage implements are widely used in the cultivation of many agricultural crops. Structurally, the working units of rotary implements are located (installed) on the frame, as a rule, sequentially one after the other. This reduces the maneuverability of the tillage unit, increases the material consumption of the implement and the energy consumption of the technological operation. In the rotary tillage tool developed at Kazan State Agrarian University for pre-sowing soil cultivation, these disadvantages are eliminated by installing a spiral-screw working unit and a section of active ellipsoidal needle disks on the frame coaxially. The research was carried out in order to determine and substantiate the design parameters of the elliptical needle disk. A theoretical dependence is obtained to substantiate the angle α of inclination of the major axis of the ellipsoid disk to the axis of rotation. It was revealed that its rational value must correspond to the condition: α> 44°…62°. An expression for determining the number of needles on a disk is given. The calculation carried out with a disk diameter D= 0.4 m, an angle α= 65 °, an indicator of a kinematic mode λ= 2, a mulching depth a= 0.04 m, a ridging h= 0.004 m showed that a rational number of needles per disc k= 16. Analytically, a theoretical expression for determining the angle of inclination of the needles to the axis of rotation has been derived. The calculation performed at α= 65 ° revealed that the first needle is inclined to the axis of rotation at a minimum angle jmin= 65 °, the fifth and thirteenth needles are inclined to the axis of rotation at an angle of 90 °, the ninth needle is inclined to the axis of rotation at a maximum angle jmax= 115 °. Also obtained are theoretical dependences for determining the angle of attachment of the needles on the hub and the length of the needles along the entire perimeter of the disk. The calculation showed that each needle is fixed on the disc hub at its calculated angle of inclination, equal to 29.0°...32.6°, and the length of the needles along the perimeter of the hub varies within 0.1372 ... 0.1503 m

Integrated Design and Evaluation of a Soil-Covering and Film-Mulching Device for Sugarcane Transverse Planters

To solve the problem that the covering device of sugarcane cannot be adequate for the agronomic standards of seed cane setts planting, a soil-covering and film-mulching device for sugarcane transverse planting was designed. The device includes a soil-covering part, soil-compacting part, and film-mulching part. Through theoretical analysis of key components, the factors affecting the cane seed covering quality for the device were obtained. A quadratic orthogonal rotation regression test was conducted by a homemade prototype to explore the effects of disk diameter, central distance, disk depth in soil, and dip angle on soil covering thickness. The results showed that the above factors all have an extremely significant effect on the soil covering thickness, and the effect degree of each factor from high to low is central distance, disk depth in soil, dip angle, and disk diameter within the range of test parameters. The optimal parameter combination, with the disk diameter, the dip angle, the central distance, the disk depth in soil, and the diameter of the soil-compacting wheel being 304.7 mm, 55.1°, 386.5 mm, 32.4 mm, and 300 mm, respectively, was obtained by Design-Expert software and verified by comprehensive field tests. The results showed that the covering thickness is in the range of 94–111 mm, the average value is 102.6 mm, and the breakage rate is no more than 2.6%. The emergence rate is 86.4%, which is an improvement of 9.3% over that of a traditional covering device. The results suggested that the device can conform to the agricultural covering standard of sugarcane planting and provide a design basis for the application and popularization of the soil-covering and film-mulching device.

Collective Dynamics in Quasi-One-Dimensional Hard Disk System

We present the results of molecular dynamic studies of collective dynamics in a system of hard disks confined to a narrow quasi-one-dimensional (quasi-1D) channel. The computer simulations have been performed for the specific channel width of 3/2 of disk diameter in which the disk arrangement at close packing resembles zigzag ordering characteristic of a vertically oriented two-dimensional (2D) triangular lattice. In such a quasi-1D system, which is intermediate between 1D and 2D arrays of hard disks, the transverse excitations obey very specific dispersion law typical of the usual optical transverse modes. This is in a sharp contrast both to the 1D case, where transverse excitations are not possible, and to the 2D case, where the regular shear waves with a propagation gap were observed. Other peculiarities of the dispersion of collective excitations as well as some results of disk structuring and thermodynamics of the quasi-1D hard disk system are presented and discussed for a range of hard disk densities typical for fluid and distorted crystal states.

Retinal Microvascular Changes in Subtypes of Ischemic Stroke

Aims: Retinal microvasculature shares prominent similarities with the brain vasculature. We aimed to assess the association between retinal microvasculature and subtypes of ischemic stroke.Method: We consecutively enrolled ischemic stroke patients within 7 days of onset, who met the criteria of subtype of atherothrombosis (AT), small artery disease (SAD), or cardioembolism (CE) according to a modified version of the Trial of Org 10172 in Acute Stroke Treatment (NEW-TOAST). Digital fundus photographs were taken within 72 h of hospital admission using a digital camera (Topcon TRC-50DX), and fundus photographs were semi-automatically measured by software (Canvus 14 and NeuroLucida) for retinal vasculature parameters.Results: A total of 141 patients were enrolled, including 72 with AT, 54 with SAD, and 15 with CE. AT subtype patients had the widest mean venular diameter within 0.5–1.0 disk diameter (MVD0.5−1.0DD) followed by SAD and CE subtypes (86.37 ± 13.49 vs. 83.55 ± 11.54 vs. 77.90 ± 8.50, respectively, P = 0.047); CE subtype patients had the highest mean arteriovenous ratio within 0.5–1.0 disk diameter (MAVR0.5−1.0DD) followed by the AT and SAD subtype groups (0.97 ± 0.03 vs. 0.89 ± 0.99 vs. 0.89 ± 0.11, respectively, P = 0.010); SAD subtype patients were found with the highest mean venular tortuosity within 0.0–2.0 disk diameter (MVT0.0−2.0DD) followed by the AT and CE subtypes (1.0294 ± 0.0081 vs. 1.0259 ± 0.0084 vs. 1.0243 ± 0.0066, respectively, P = 0.024). After adjusting for clinic characteristics, MVD0.5−1.0DD was significantly different among AT, SAD, and CE subtypes (P = 0.033). By receiver operating characteristic curve analysis, MVD0.5−1.0DD predicted the AT subtype (area 0.690, 95% confidence interval, 0.566–0.815), with a cutoff value of 82.23 μm (sensitivity 61.1%, specificity 73.3%).Conclusion: Retinal MVD0.5−1.0DD (>82.23 μm) might be associated with the AT stroke subtype; however, we need large-scale prospective studies in future to explore the underlying mechanism and causal explanation for this finding.

Altered fovea in AQP4-IgG–seropositive neuromyelitis optica spectrum disorders

ObjectiveTo investigate disease-specific foveal shape changes in patients with neuromyelitis optica spectrum disorders (NMOSDs) using foveal morphometry.MethodsThis cross-sectional study included macular spectral domain optical coherence tomography scans of 52 eyes from 28 patients with aquaporin-4 immunoglobulin G (AQP4-IgG)-seropositive NMOSD, 116 eyes from 60 patients with MS, and 123 eyes from 62 healthy controls (HCs), retrospectively, and an independent confirmatory cohort comprised 33/33 patients with NMOSD/MS. The fovea was characterized using 3D foveal morphometry. We included peripapillary retinal nerve fiber layer (pRNFL) thickness and combined macular ganglion cell and inner plexiform layer (GCIPL) volume to account for optic neuritis (ON)-related neuroaxonal damage.ResultsGroup comparison showed significant differences compared with HC in the majority of foveal shape parameters in NMOSD, but not MS. Pit flat disk area, average pit flat disk diameter, inner rim volume, and major slope disk length, as selected parameters, showed differences between NMOSD and MS (p value = 0.017, 0.002, 0.005, and 0.033, respectively). This effect was independent of ON. Area under the curve was between 0.7 and 0.8 (receiver operating characteristic curve) for discriminating between NMOSD and MS. Pit flat disk area and average pit flat disk diameter changes independent of ON were confirmed in an independent cohort.ConclusionsFoveal morphometry reveals a wider and flatter fovea in NMOSD in comparison to MS and HC. Comparison to MS and accounting for ON suggest this effect to be at least in part independent of ON. This supports a primary retinopathy in AQP4-IgG–seropositive NMOSD.

Pengaruh Diameter Piringan Katup Limbah Terhadap Tekanan Aliran Balik Dalam Pompa Hidram

Pompa hidram bekerja dengan memanfaatkan proses palu air. Terjadinya palu air akan mengakibatkan sebagian air menuju ke tabung udara dan sebagian lagi akan mengalami aliran balik pada pipa penggerak. Diameter piringan katup limbah mempengaruhi laju aliran dan gaya tekan di dalam badan pompa, sehingga akan mempengaruhi besarnya tekanan balik yang terjadi. Oleh sebab itu perlu dilakukan penelitian lebih lanjut mengenai pengaruh diameter piringan katup limbah terhadap tekanan aliran balik dalam pipa penggerak pompa hidram. Penelitian menggunakan variasi diameter piringan katup limbah 35 mm, 40 mm, 45 mm, 50 mm, dan 53 mm. Penelitian dilakukan dengan menggunakan kamera berkecepatan tinggi yaitu 960 fps, untuk merekam aliran balik yang sudah disemprotkan gliter sebelumnya. Sehingga didapatkan jarak pergerakan gliter untuk mendapat kecepatan dan pada akhirnya mendapat tekanan. Hasil dari penelitian menunjukkan diameter piringan katup limbah berpengaruh terhadap tekanan balik yang terjadi. Dimana head tekanan tertinggi terjadi pada diameter piringan katup limbah 40 mm sebesar 42.76 N/m2. Diikuti dengan debit pemompaan terbesar pada diameter piringan 42.88 mm sebesar 2.3 liter/menit. Selain tekanan, semakin besar diameter piringan katup limbah akan meningkatkan frekuensi dan efisiensi pompa hidram. Namun debit pembuangan menurun seiring bertambahnya diameter piringan. Hydram pump works by utilizing the water hammer process. Water hammer that take place some water flow into the air tube and some other will back into the drive pipe. The waste valve disk diameter affects the flow rate and the pressure force inside the pump body, so that it will affect the back pressure. Therefore it is necessary to conduct further research on the effect of the waste valve disk diameter to backflow pressure in the hydram pump drive pipe. The work used variations in diameter of 35 mm, 40 mm, 45 mm, 50 mm, and 53 mm. The flow pattern was recorded using a high-speed camera with 960 fps. The water was mixing with glitters. The glitter movement distance is obtained to get the speed and then its pressure. The results that show the diameter of the waste valve influences the back pressure. Finally the highest pressure is on the disk diameter 40 mm at 42.76 N/m2. Furthermore, the largest pumping debit was on a 42.88 mm disk diameter at 2.3 liters/minute. In addition, the larger valve disk diameter cause the higher frequency and efficiency. However, the waste debit decreases with increasing disk diameter.

Optimization of parameters and operating modes of the rotary working body for harrowing agricultural crops

The rotary working body with evenly spaced needles along the perimeter is a flat disk (rotating in a longitudinally vertical plane). The technological process of interaction with the soil consists in the fact that when the rotary disk is rolled in the soil layer, the needle is inserted into it, crushing and shifting the soil in the direction of rotation. The degree of soil loosening, rotating freely in a longitudinal vertical plane of the needle disk on the axis depends on several parameters: disk diameter, number of needles, speed, and soil properties. An experimental study of needle working bodies was performed in terms of the influence of the disk size, the number of needles and the speed of movement on the process of soil crumbling.

Measurement Eccentricity the Moon’s Orbit with Image Analysis Technique by Using Tracker Software

One of the interesting physical phenomenon to be studied is about eccentricity of the Moon's orbit on the movement of the Earth and the Moon as explained in Kepler's Law. In order to explain the phenomenon,several research has been done to determine the measurement accuracy of Moon disk diameter using Trackers and to know the result of the eccentricity value in the application of Kepler's Law. This research can produce eccentricity values accordance with the application of Kepler’sLaw. The research method used is Image Analysis Techniqueassisted with Tracker. The result of this research shows that the eccentricity value obtained is 0.07 ± 0.01. This is in accordance with Kepler's first Law which stated that orbits of each planet and satellite is an ellipse and has an eccentricity value of 0 <e <1. The value of eccentricity obtained has accuracy of 22%,if it compared with the actual value.Whereas, if it compared with the value of ephemeris then the value of accuracy is 8%.