Orbital Length Research Articles

Precise Orbit Determination of BDS-2 and BDS-3 Using SLR

The BeiDou Navigation Satellite System (BDS) of China is currently in the hybrid-use period of BDS-2 and BDS-3 satellites. All of them are equipped with Laser Retroreflect Arrays (LRAs) for Satellite Laser Ranging (SLR), which can directly obtain an independent, sub-centimetre level of distance measurement. The main purpose of this contribution is to use the solely SLR Normal Points (NPs) data to determinate the precise orbit of BDS-2 and BDS-3 satellites, including one Geostationary Earth Orbit (GEO), three Inclined Geo-Synchronous Orbits (ISGO), and one Medium Earth Orbit (MEO) of BDS-2 satellites, as well as four MEO of BDS-3 satellites, from 1 January to 30 June 2019. The microwave-based orbit from Wuhan University (WUM) are firstly validated to mark and eliminate the bad SLR observations in our preprocessing stage. Then, the 3-, 5-, 7-, and 9-day arc solutions are performed to investigate the impact of the different orbital arc lengths on the quality of SLR-derived orbits and test the optimal solution of the multi-day arc. Moreover, the dependency of SLR-only orbit determination accuracy on the number of SLR observations and the number of SLR sites are discussed to explore the orbit determination quality of the 3-,5-, 7-, and 9-day arc solutions. The results indicate that (1) during the half-year time span of 2019, the overall Root Mean Square (RMS) of SLR validation residuals derived from WUM is 19.0 cm for BDS-2 GEO C01, 5.2–7.3 cm for three BDS-2 IGSO, 3.4 cm for BDS-2 MEO C11, and 4.4–5.7 cm for four BDS-3 MEO satellites respectively. (2) The 9-day arc solutions present the best orbit accuracy in our multi-day SLR-only orbit determination for BDS IGSO and MEO satellites. The 9-day overlaps median RMS of BDS MEO in RTN directions are evaluated at 3.6–5.7, 12.4–21.6, and 15.6–23.9 cm respectively, as well as 5.7–9.6, 15.0–36.8, and 16.5–35.2 cm for the comparison with WUM precise orbits, while these values of BDS IGSO are larger by a factor of about 3–10 than BDS MEO orbits in their corresponding RTN directions. Furthermore, the optimal average 3D-RMS of 9-day overlaps is 0.49 and 1.89 m for BDS MEO and IGSO respectively, as well as 0.55 and 1.85 m in comparison with WUM orbits. Owing to its extremely rare SLR observations, the SLR-only orbit determination accuracy of BDS-2 GEO satellite can only reach a level of 10 metres or worse. (3) To obtain a stable and reliable SLR-only precise orbit, the 7-day to 9-day arc solutions are necessary to provide a sufficient SLR observation quantity and geometry, with more than 50–80 available SLR observations at 5–6 SLR sites that are evenly distributed, both in the Northern and Southern Hemispheres.

A Consistent, Reliable Landmark to Assist in Placement of Orbital Floor Reconstruction Plates After Blowout Fractures.

To define a reliable and consistent landmark, the superior posterior wall of the maxillary sinus, and to describe how this landmark can be used when repairing orbital floor fractures. Retrospective chart review. Patients >18 years old diagnosed with unilateral orbital floor and/or zygomaticomaxillary complex fractures. The distance from the inferior orbital rim to the superior posterior wall of the maxillary sinus (landmark distance), and the distance from the landmark to the entrance of the optic canal were reported. Eighty patients were included in the study. Each had unilateral isolated orbital floor fractures (n = 46) or unilateral zygomaticomaxillary complex fractures with an orbital floor component (n = 34). The contralateral eye in all patients was uninjured, and was used as an internal control. In orbital floor fractures, the mean landmark distance was 38.8 ± 1.4 mm, with a mean distance on the normal side of 38.8 ± 1.6 mm (P = 0.49). Distance to the optic canal on the injured side in isolated orbital floor fracture patients was 9.0 ± 0.8 mm with the same measurement on the normal side being 8.8 ± 0.7 (P = 0.21). In the setting of zygomaticomaxillary complex fracture, the orbital floor length was 38.2 ± 1.3 mm with a mean normal floor length of 37.8 ± 1.1 mm (P = 0.18). The mean distance from the superior posterior wall to optic canal in zygomaticomaxillary complex fractured orbits was 9.2 ± 1.1 mm with a normal side mean length of 9.5 ± 1.0 mm (P = 0.23). No significant difference was found between the measured distances in the fractured orbit and its normal counterpart for both fracture groups. The superior posterior wall of the maxillary sinus is a reliable landmark that can be used to assist in placement of an orbital floor reconstructive plate. The landmark is unchanged despite the presence of an orbital floor or zygomaticomaxillary sinus fracture.

Anthropometric study of the cranial parameters using Computed Tomography (CT) scan to establish cephalic index of a sampled population in Calabar, Nigeria

Background: Ethnic characteristics of individuals are best described with the skull. Cranial index is one of the most important variables for determining sexual dimorphism and of course racial differences. Parameters used in establishing cephalic index vary considerably depending on the age, sex, geographical habitat, ethnic background of the individuals involved and the methods employed. Such has not been documented in Calabar, especially with the use of advanced imaging modality such as the Computed Tomography (CT) scans. This is the rationale of the study.Objective: To determine the cephalic index of Nigerians residing in Calabar using CT scan.Materials and Methods: A total of 200 cranial Brivo 385 16 slice CT scan images of Nigerians aged from 18 to 87 years were obtained from the Asi-Ukpo Diagnostic Medical Centre Calabar. A simple random probability sampling technique was employed. Variables measured were the Maximum Cranial Length (MCL), Maximum Cranial Width (MCW), Bizygomatic Length (BZL) and the Orbital Length (OBL). The cephalic index was obtained by measuring the ratio of the maximum head width (MCW) or the Biparietal Diameter (BPD) to maximum head length (MCL) or the antero-posterior diameter then multiplied by 100.Results: Cranial length was 182.9 ± 0.657mm in males and 178.53 ± 0.09mm in females. Cranial width was 138.59 ± 0.56mm in males and 137.21 ± 0.65mm in females. The orbital length was 34.35 ± 0.31mm in males and 33.37 ± 0.29mm in females while bizygomatic length was 130 ± 0.31mm in males and 127.54 ± 0.84mm in females. Cranial index was 76.09mm in males and 75.81mm in females. No significant difference between males and females of the study population as the subject appears to be largely mesocephalic (p<0.05).Conclusion: Cranial index of the study sampled population is majorly mesocephalic. Therefore, CT scan is very important a tool in the assessment of cranial parameters in anthropometry.Keywords: Anthropometry, Calabar, Cranial index, Computed Tomography, Mesocephalic

S3-04 SESSION 3: FACIOCRANIOSYNOSTOSIS – PART I EARLY CRANIOFACIAL GROWTH IN SYNDROMIC SYNOSTOSIS: IMPLICATIONS FOR ADVANCEMENT PROCEDURES

Introduction: As subcranial and transcranial advancements become possible at younger ages, it is important to better understand the growth profile of syndromic synostosis in the first years of life to influence decision-making on surgical timing. The objective of this study is to create a growth plot of midface and mandible growth in untreated Crouzon patients to determine if vertical and horizontal growth is linear or multiphasic. Methods: We performed a retrospective review of all patients who had CT scans performed in our Center with the diagnosis of Crouzon syndrome. Images after any subcranial or transcranial midface surgeries were excluded. Using custom Slicer software, we automatically aligned the scans to a Frankfort Horizontal plane (bilateral porion and left orbitale) and measured the orbital length (sella to orbitale), maxillary length (sella to nasal spine), maxillary height (nasion to nasal spine), and effective mandible length (sella to gnathion). Distances were plotted against age for linear regression analysis. Results: We included 24 patients with 57 scans at ages 0 to 8.5 years. On scatter plots of facial dimensions, the best-fit linear regression for variables were two age lines 0-2yr and 2-8yr (* p<0.05). Conclusion: The Crouzon cohort demonstrated both horizontal and vertical midface growth over the first two years of life. After two years, the rate of vertical growth continued but decreased, and horizontal growth plateaued. Of interest, mandible length followed the same abnormal growth profile of midface vertical growth, suggesting that growth restriction is bi-maxillary in these patients. Clinical midface deficiency resulting from deficient maxillary horizontal growth may mask absolute retrognathia. This work is continuing to include other craniofacial syndromes and to compare to age-matched normal controls to increase our understanding of differential maxillomandibular growth charts in these complex cases.

Influence of orbital morphology on proptosis reduction and ocular motility after decompression surgery in patients with Graves' orbitopathy.

PurposeOrbital decompression surgery is performed in patients with Graves’ orbitopathy to treat dysthyroid optical neuropathy (DON) and reduce disfiguring proptosis. The intended proptosis reduction can deviate from the postoperative result and changes of motility with consecutive diplopia can occur. We performed a retrospective study to identify anatomical factors in computed tomography (CT), which influence the surgical effect and postoperative ocular motility and diplopia.MethodsPre- and postoperative CT-scans of 125 eyes of 68 patients, who mainly underwent a balanced orbital decompression for disfiguring proptosis (≥18mm Hertel Index), have been analyzed. Proptosis, ductions, misalignment and diplopia were assessed before and after surgery. Medial and lateral orbital wall length, conus angle, depth of ethmoidal sinus, orbital surface, length of medial and orbital defect, depth of tissue prolapse and horizontal muscle diameters were analyzed in CT scans before and after surgery. With linear regression and multivariate analyses these parameters have been correlated with postoperative proptosis, abduction deficit, deviation and binocular single vision (BSV).ResultsProptosis could be reduced by 5.3±2mm. Patients with <5mm proptosis reduction had significantly less often new onset of diplopia compared to patients with >5mm reduction (13% vs. 56%, p = 0.02). Multiple linear regression showed a significant correlation between tissue prolapse and depth of the ethmoidal sinus as well as age (p<0.001, r = 0.71). Proptosis reduction could not be predicted by tissue prolapse, defect length or depth of ethmoidal sinus. The abduction deficit correlated significantly with tissue prolapse and orbital surface area (p<0.001, r = 0.37) but not with the horizontal muscle diameter.ConclusionWe were able to show that orbital morphology influences the outcome of balanced orbital decompression surgery in terms of proptosis reduction and motility. However, the rather low coefficients of correlation show that the surgical outcome cannot be predicted with simple CT measurements, although risk factors for postoperative abduction deficit could be found. Therefore, preoperative planning should consider especially the orbital surface area and depth of ethmoidal sinus. Patients should be informed about the higher risk of diplopia with higher proptosis reduction.

Analysis and interdependence of morphometric characters in the Hill stream fish Mastacembelus armatus (Lacepede) from Garhwal Himalaya

Study of morphometric characters is generally carried out for species identification in fish biology. It includes the measurements of all body lengths and their inter relationships in terms of ratios and percentages to the independent lengths (Total length, standard length and head length). Present paper deals with the analysis of various morphometric characters with species characteristics in Mastacembelus armatus (Lacepede), which is one of the most important eel like hillstream fish belonging to order Mastacembeliformes and family Mastacembelidae from river Western Nayar (290 45’ to 300 15’ latitude and 780 34’ to 790 12’ longitude ). Total length, standard length and head lengths were considered as an independent variables in ratio of which other lengths (caudal length, pre orbital length, post orbital length, maximum body depth, snout length and eye diameter) were analysed. The maximum size of fish was observed as 60 cm and the minimum being 10 cm. By using regression and correlation analysis, the modelling of data is presented to find out their interrelationship. The closest correlation was in between total length and standard length (r= 0.999) and the farthest between total length and caudal length ( r= 0.878). The linearity of regression was tested by the analysis of variance (ANOVA) which showed that all the relationships were significant at the level of 5 % significance. The multivariate analysis was also done by using cluster technique which sowed except caudal length rest all characters were forming a close cluster.

Morphological comparison of western and eastern populations of Caspian kutum, Rutilus kutum (Kamensky, 1901) (Cyprinidae) in the southern Caspian Sea

This study aimed to investigate morphological differences of western and eastern populations of Caspian kutum Rutilus kutum in the southern Caspian Sea and its providing length-weight relationships and condition factor (CF). A 13-landmark based morphometric truss network system was used to investigate the hypothesis of population fragmentation of western and eastern populations of this species. The studied populations were differentmorphologically based on pre anal, body height, distance from pectoral fin to ventral fin, distance from pectoral fin to anal fin, caudal peduncle length, head length, pre orbital, pre ventral, and dorsal length. The results also revealed a negative allometry (b<3) of length-weight relationships for both sexes. Maximum condition factors was found in March. The results suggest distinct stocks in the western and eastern of Caspian Sea for fisheries management.

Morphological variations in marine pufferfish and porcupinefish (Teleostei: Tetraodontiformes) from Tamil Nadu, southeastern coast of India

In the present study, morphological variations in 14 species of two families, Tetraodontidae and Diodontidae, were examined for individuals collected from five different centres in Tamil Nadu in the southeastern coast of India. Twenty-seven morphological measurements and four meristic characters were taken and used for multivariate analyses such as discriminant function analysis (DFA) &amp; MANOVA. DFA revealed that the first two functions accounted for more than 75% variation between the species. Negative allometric values were observed on head length (HL), orbital length (OL), pupil diameter (PD), interorbital length (IOL), pectoral-fin length (PEL), caudal peduncle depth (CPD), dorsal to pectoral fin distance (DPFD), caudal peduncle length (CPL) and post-pectoral-fin length (POPFL) measurements. Also, MANOVA supported the DFA results. Additions, allometric relationships, and meristic variations were observed for most of these species. Moreover, this is the first attempt to describe a greater number of morphological features of the species belonging to the order Tetraodontiformes.

Experimental investigation of the transition energy [formula omitted] in the isochronous mode of the HIRFL-CSRe

The Isochronous Mass Spectrometry (IMS) based on storage rings is a powerful technique for mass measurement of short-lived exotic nuclei. The transition energy γt of the storage ring is a vital parameter of the IMS technique. It is difficult to measure the γt and its relation to momentum spread or circulating length, especially to monitor the variation of γt during experiments. An experimental investigation on the γt has been performed for the IMS experiment at the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou (HIRFL-CSRe). With the velocity measured by two time-of-flight (TOF) detectors, the γt as a function of orbital length can be determined. The influences of higher order magnetic field components on the γt function were inferred for isochronous correction. This paper introduces and investigates the influence of dipole magnetic fields, quadrupole magnetic fields and sextupole magnetic fields on the γt function. With the quadrupole magnets and sextupole magnets corrections, a mass resolution of 171332 (FWHM) and σ(T)∕T=1.34×10−6 were reached, which shall be compared with 31319 (FWHM) and σ(T)∕T=7.35×10−6 obtained without correction.

New Ru(II) half sandwich complexes bearing the N,N′ bidentate 9-ethyl-N-(pyridin-2-ylmethylene)9H-carbazole-3-amine ligand: Effects of halogen (Cl−, Br− and I−) leaving groups versus in vitro activity on HepG2 cancer cells, cell cycle, fluorescence study, cellular accumulation and DFT study

Three new ruthenium(II) complexes [(η6-p-cymene)RuX(L)]PF6 (X = Cl (1), Br (2) and I (3)) with 9-ethyl-N-(pyridin-2-ylmethylene)9H-carbazole-3-amine (L) have been prepared and characterised by elemental analysis and different spectral techniques (NMR studies, IR and HR-Mass spectroscopy). The molecular structure of the [(η6-p-cymene)RuI(L)]PF6 (3) complex was determined by single crystal XRD. The geometry around the Ru(II) centre is that of a classical “piano stool” with the iodine, the N,N′ ligand bonding in a bidentate manner and the π-bonds of the p-cymene occupying the coordination sites. In vitro studies of the complexes 1–3 on HepG2 human liver cancer cells showed excellent inhibitory concentration (IC50) values between 22 and 30 μM. The halogen leaving groups Cl−, Br− and I− presented in the complexes 1–3 showed a significant effect. Interestingly complex 3 displayed a significant growth inhibitory IC50 value of 22 μM compared to the other two complexes. Furthermore, cell cycle, cytotoxic, nuclear studies and cellular accumulation have shown that the new Ru(II) half sandwich complexes 1–3 were effective against HepG2 cancer cell proliferation. Density functional theory (DFT) was used to calculate the relevant molecular orbital energy levels, binding energies, bond angles and bond lengths of the synthesised Ru(II) complexes. The DFT study of the complexes 1–3 further supported the biological activity of the complexes and showed good agreement with experimental results.

A method to measure the transition energy [formula omitted] of the isochronously tuned storage ring

The Isochronous Mass Spectrometry (IMS) is a powerful technique developed in heavy-ion storage rings for measuring masses of very short-lived exotic nuclei. The IMS is based on the isochronous setting of the ring. One of the main parameters of this setting is the transition energy γt. It has been a challenge to determine the γt and especially to monitor the variation of γt during experiments. In this paper we introduce a method to measure the γt online during IMS experiments by using the acquired experimental data. Furthermore, since the storage ring has (in our context) a relatively large momentum acceptance, the variation of the γt across the ring acceptance is a source of systematic uncertainty of measured masses. With the installation of two time-of-flight (TOF) detectors, the velocity of each stored ion and its revolution time are simultaneously available for the analysis. These quantities enabled us to determine the γt as a function of orbital length in the ring. The presented method is especially important for future IMS experiments planned at the new-generation storage ring facilities FAIR in Germany and HIAF in China.

A multigear protocol for sampling crayfish assemblages in Gulf of Mexico coastal streams

Identifying an effective protocol for sampling crayfish in streams that vary in habitat and physical/chemical characteristics has proven problematic. We evaluated an active, combined-gear (backpack electrofishing and dipnetting) sampling protocol in 20 Coastal Plain streams in Louisiana. Using generalized linear models and rarefaction curves, we evaluated environmental and gear (separate and combined) effects on crayfish catch-per-unit-effort (CPUE), orbital carapace lengths, sex ratios, frequencies of rare species, and sample richness. Although pooled data from combined gears showed greater total numbers of crayfishes, CPUE, and richness compared to either gear individually, combined gear and backpack electrofisher results differed minimally. Overall, richness was negatively related to specific conductance, indicating potential agricultural influence. Neither crayfish sex ratios, lengths, nor frequencies of rare species differed by gear; however, combining data from both gears ensured crayfish were captured in all study streams, which was not found for electrofishing or dipnetting alone. Species accumulation and rarefaction curves indicated sampling was sufficient for recording crayfish diversity at the scale of the study and that adding streams (versus sites within streams) would be most effective for watershed-scale studies. Our results suggested the combined gear protocol was effective for assessing crayfish population and assemblage characteristics in these Coastal Plain streams.

Mechanics and dynamics of orbital drilling operations

This paper presents a general and unified model which predicts tool – workpiece engagement, chip geometry, cutting forces, chatter stability and hole surface errors simultaneously. The tool-workpiece engagement along the tool path is identified by a newly introduced, computationally fast line-intersection algorithm and used in predicting the chip thickness. The contribution of bottom edges to the cutting process is included. The dynamics of the system have been modeled including time-varying delay contributed by the combination of spindle speed and orbital tool motion. The stability of the orbital drilling is solved in discrete-time and frequency domains. Three dimensional stability lobes and hole surface errors are predicted as a function of tool position along the orbital path, spindle speed and pitch length of the path. The mechanics, stability and surface location error models have been experimentally validated by conducting orbital drilling of holes. The model is intended for optimal selection of tool geometry, orbital and tangential feeds, and spindle speeds without causing chatter, violating dimensional tolerances and overloading of the machine.

Osteologic analysis of ethnic differences in supernumerary ethmoidal foramina: implications for endoscopic sinus and orbit surgery.

Knowledge of the position of the ethmoidal arteries is critical to enable safe endoscopic sinus and orbital surgery. The presence of a third or "middle" ethmoid variant has recently become more relevant as endoscopic intraconal surgery continues to advance. The purpose of this study was to quantify the presence of supernumerary (ie, over 2) ethmoid foramina in different ethnicities and genders. Morphometric osteologic measurements were performed in 273 orbits. Prevalence of supernumerary ethmoid foramina and orbital length data were obtained from human skulls of Asian (n = 54), Caucasian (n = 70), African (n = 39), Hispanic (n = 49), and Middle Eastern (n = 61) derivation. Correlations between gender, ethnicity, symmetry, orbital floor, and lamina papyracea length were assessed by analysis of variance, paired t test, and χ2 test. Supernumerary foramina were identified in 95 of 273 orbits (34.79%). A significantly higher prevalence was seen in Asian (42.59%), African (41.02%), and Hispanic (41.00%) skulls as compared with Caucasian (25.71%) and Middle Eastern (22.95%) skulls (p < 0.05 for all). The length of the orbital floor was significantly shorter in the Asian (3.35 ± 1.52 cm) specimens (p < 0.01). Asians were found to have the highest risk of ethmoid artery injury compared with the other ethnic groups (ratio of number of supernumerary foramina to orbital floor length = 0.72). Supernumerary ethmoidal foramina were common among all orbits studied. Orbits of Asian and African derivation had significantly greater numbers of ethmoidal foramina, both unilaterally and symmetrically and within a shorter orbital length, suggesting a greater proximity between the ethmoidal vessels. Surgeons should be alert to the possible presence of middle ethmoidal vessels during endoscopic sinus and orbital approaches.

Studies on morphological variation in three barbin fishes (Cyprinidae:Barbinae) from different water areas of Manipur, India

A total of two hundred and seventy samples of three barbin fish species viz. Puntius chola, Puntius sophore and Pethia manipurensis (Cyprinidae: Barbinae) were investigated for morphometric variations from nine different water areas of Manipur. Twenty reliable morphometric characters were measured in each sample and evaluated with individual species and compared same in each study area by various standard analyses of difference to examine the implication of morphometric variations among populations. The species wise and population wise descriptive statistics viz., mean, standard variation, standard error of mean and the Principle Component Analysis (PCA) were carried out. Among the morphometric characters, Pre dorsal length (LPRD), Orbital length (LO) and Post orbital length (LPO) are insignificant having p value of 0.217, 0.259 and 0.215 respectively. The result of first three components by PCA were 69.62 % (1st), 77.627 % (2nd) and 83.214 % (3rd) which are sufficient to describe the variation among the populations. Discriminant function analysis of the first two functions of various measurements of morphometric characters of three fish species under study reveals that specimens of Puntius chola and P. sophore have high morphological variations whereas specimens of Pethia manipurensis have more or less variations among the populations. The detected phenotypical divergence between specimens revealed the fact of existing of morphologically separated stocks within the samples may imply as a possibility among the extent of phenotypic heterogeneity and the geographic distance among the populations. The present study reveals that the population of two species, Puntius chola and P. sophore are separate stock as their geographical sites whereas the population of P. manipurensis is same stock in spite of different geographical sites.

Studies on morphological variation in three barbin fishes (Cyprinidae:Barbinae) from different water areas of Manipur, India

A total of two hundred and seventy samples of three barbin fish species viz. Puntius chola, Puntius sophore and Pethia manipurensis (Cyprinidae: Barbinae) were investigated for morphometric variations from nine different water areas of Manipur. Twenty reliable morphometric characters were measured in each sample and evaluated with individual species and compared same in each study area by various standard analyses of difference to examine the implication of morphometric variations among populations. The species wise and population wise descriptive statistics viz., mean, standard variation, standard error of mean and the Principle Component Analysis (PCA) were carried out. Among the morphometric characters, Pre dorsal length (LPRD), Orbital length (LO) and Post orbital length (LPO) are insignificant having p value of 0.217, 0.259 and 0.215 respectively. The result of first three components by PCA were 69.62 % (1st), 77.627 % (2nd) and 83.214 % (3rd) which are sufficient to describe the variation among the populations. Discriminant function analysis of the first two functions of various measurements of morphometric characters of three fish species under study reveals that specimens of Puntius chola and P. sophore have high morphological variations whereas specimens of Pethia manipurensis have more or less variations among the populations. The detected phenotypical divergence between specimens revealed the fact of existing of morphologically separated stocks within the samples may imply as a possibility among the extent of phenotypic heterogeneity and the geographic distance among the populations. The present study reveals that the population of two species, Puntius chola and P. sophore are separate stock as their geographical sites whereas the population of P. manipurensis is same stock in spite of different geographical sites.

A Quick View on Biology of Near Threatened Peacock Eel (&lt;i&gt;Macrognathus aculeatus&lt;/i&gt;) in Khulna Region of Bangladesh

The Peacock eel, Macrognathus aculeatus is a near threatened highly valuable small indigenous species in Bangladesh. It is not only toothsome nutritive table fish but also notable aquarium species but still rely on natural stock. Keeping in mind the paucity of information on the biology which is crucial to develop artificial propagation and culture technique of this species, the present research was performed as an attempt to contribute to the information on the taxonomy and other biological aspects of M. aculeatus. Total 50 samples were collected from Khulna region during April to May 2014 to assay. The taxonomical study revealed that the total length, standard length, head length, eye diameter, pre and post orbital length; length of dorsal, anal and caudal fin; length of upper and lower jaw; body depth and width, distance between dorsal fin to caudal fin ranged from 17.00-21.00, 15.00-19.00, 0.80-3.00, 0.20-0.40, 0.50-2.10, 0.30-1.70, 3.10-6.70, 3.50-6.30, 0.50-1.50, 0.30-1.00, 0.70-1.80, 0.90-2.30, 0.60-1.20, 0.70-2.40 cm respectively, additionally meristic character’s formula appeared like D. 19 - 39, A. 11 - 18, C. 29 – 52, L. 11-15 and number of eye spots on dorsal fin, 3-10. Turning to the biological inquiry which showed that the fish weight (g), gonad weight (g), liver weight (g), gut weight (g), gonadosomatic, alimentosomatic and hepatosomatic index and condition factor ranged from 15.10-28.60, 2.32-3.18, 0.029-0.044, 0.64-1.08, 9.69-14.79, 2.58-4.15, 0.11-0.19 and 0.30-0.40 respectably. The mean values of hepatosomatic and alimentosomatic indices persuaded greater liver activity and feeding intensity in M. aculeatus. Moreover, stomach content depicted that the diet of peacock eel composed of small fish species, small prawn, prawn larvae, earthworm, water strider, insects pupae, Metaphire posthuma, Caenorhabditis, sand and mud for instance, which in brief expressed that M. aculeatus is omnivorous in its feeding habits. Indeed, this preliminary research outcome would be utile for the species identification, seed production, developing culture technologies as well as biodiversity conservation of this near threatened fish species.

Abstract P23: Changes in Skull Dysmorphology with Age in Unilateral Coronal Synostosis

PURPOSE: While modern research on coronal craniosynostosis has vastly widened our breadth of knowledge regarding treatment of the condition, the mechanism underlying the development of the deformity remains uncovered and largely uninvestigated. This study evaluates midface and skull base development in nonsyndromic unilateral coronal synostosis (UCS), focusing on zygomatic and cranial base anatomical changes during the first year of life. Additionally, this study seeks to chronicle the changes over time in infancy in order to characterize the mechanistic progression of facial dysmorphology. METHODS: CT scans from 50 subjects were reviewed (25 UCS, 25 controls) and CT DICOM data was digitized and reconstructed. Patients were stratified into five age groups all under one year of age. A series of 42 measurements focusing on the zygoma, orbits and cranial base were taken from the scans using Materialise Mimics software (Leuven, Belgium). Statistical analysis was performed using SPSS (Armonk, NY). RESULTS: Starting at less than two months of age, significant differences are noted and persist in nasal and cribriform plate deviation (p=0.003). These differences are discernible in patients as young as 19 days old, except for the contralateral zygoma length, which only became noticeably higher in patients at the one month mark. At 2–3 months of age, the distance between the ipsilateral pterion to sella is significantly increased (p=0.003) and persists over time. Significant differences in contralateral zygomatic and orbital height and length are noted to develop and persist starting at 4–6 months of age. Patients under two months of age also demonstrated significant differences in the maxillary anteroposterior length (p=0.020), sella-basion distance (p=0.024), sphenooccipital synchrondrosis-basion distance (p=0.040), more acute orbital rim angle (p=0.037), reduced orbital width (p=0.039) and higher contralateral zygoma lengths (p=0.037) with non-uniform re-development of significant differences at later time points. A feature that was prevalent across all ages was the difference in angle of the sphenoid wing between the ipsilateral and contralateral side. The sphenoid wing ipsilateral to the fused suture consistently had a more acute angle from the midline, in comparison to the contralateral side. This difference was as high as 22 degrees in some patients. CONCLUSION: Unilateral coronal synostosis results in characteristic bony changes, but the development of this facial dysmorphology has not been chronicled over time to elucidate an underlying mechanism. This study demonstrates that the earliest changes in UCS are ipsilateral orbital changes and nasal deviation beginning before two months of age. This is then followed by changes in the contralateral zygoma and orbit. Sphenoid wing asymmetry was present in all age groups. Additionally, the ipsilateral sphenoid wing angle was consistently more acute than the contralateral sphenoid wing angle through all age groups; this further supports skull base changes as early changes in the mechanistic progression of facial dysmorphology in unilateral coronal synostosis. An understanding of the timing of development of facial features of unilateral coronal synostosis is essential for determining the optimal timeframe for intervention, and for allowing the surgeon and patient’s family to anticipate the possible need for revision surgeries for specific features.

Morphological Characterization of Two Fresh Water Eels Monopterus cuchia (Hamilton, 1822) and Ophisternon bengalense (McClelland, 1844)

Morphometric and meristic characters and truss measurements of 32 Monopterus cuchia, and of 17 Ophisternon bengalense were compared to know the population status of two fresh water eels of Bangladesh. The mean numbers of line below head were significantly different between two species. Significant differences were observed in 11 morphometric characters: Pre dorsal length (PDL), Post dorsal length (PoDL), Post anal length (PoAL), Head length (HL), Snout length (SnL), Upper jaw length (UJL), Lower jaw length (LJL), Head width (HW), Pre orbital length (PrOrL), Least body diameter (LBD) and Highest body diameter (HBD) and one truss measurement (3-5) between two species in varying degrees. For both morphometric and landmark measurements, the first and second DF (discriminant function) accounted 64.8% and 33.2% of among group variability, explaining 98% of total group variability. M. cuchia collected from Mymensingh and from Dinajpur constructed one sub-cluster and O. bengalense collected from Sathkhira and from Bagerhat constructed another sub-cluster based on the Distance of squared Euclidean dissimilarity. A correct classification of individuals into their original population from leave-one-out-classification varied between 93.3% and 94.1% by discriminant analysis. The results of the present study suggested that there was limited intermingling among populations and the populations of the species were separated from one another.J. Environ. Sci. &amp; Natural Resources, 9(1): 127-137 2016

Changing Population of Aphidius colemani in Relation to Environmental Factors

Morphometric and meristic characters and truss measurements of 32 Monopterus cuchia, and of 17 Ophisternon bengalense were compared to know the population status of two fresh water eels of Bangladesh. The mean numbers of line below head were significantly different between two species. Significant differences were observed in 11 morphometric characters: Pre dorsal length (PDL), Post dorsal length (PoDL), Post anal length (PoAL), Head length (HL), Snout length (SnL), Upper jaw length (UJL), Lower jaw length (LJL), Head width (HW), Pre orbital length (PrOrL), Least body diameter (LBD) and Highest body diameter (HBD) and one truss measurement (3-5) between two species in varying degrees. For both morphometric and landmark measurements, the first and second DF (discriminant function) accounted 64.8% and 33.2% of among group variability, explaining 98% of total group variability. M. cuchia collected from Mymensingh and from Dinajpur constructed one sub-cluster and O. bengalense collected from Sathkhira and from Bagerhat constructed another sub-cluster based on the Distance of squared Euclidean dissimilarity. A correct classification of individuals into their original population from leave-one-out-classification varied between 93.3% and 94.1% by discriminant analysis. The results of the present study suggested that there was limited intermingling among populations and the populations of the species were separated from one another.J. Environ. Sci. &amp; Natural Resources, 9(1): 139-141 2016