Monitoring and method validation of organophosphorus/organochlorine pesticide residues in vegetables and fruits by gas chromatography.

In this study, an analytical method was developed and validated for the assessment of pesticide residues in commonly consumed vegetables and fruits. Fresh samples of apple, green peas, tomatoes, and cucumbers were processed and subjected to analysis using a modified QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction technique. Subsequently, quantification of pesticide residues was conducted utilizing gas chromatography (GC)-electron capture detector. Extraction and cleanup parameters were meticulously optimized, resulting in a modification of the original QuEChERS method. This modification aimed to reduce solvent consumption, making the study more environmentally friendly. The developed method was validated in terms of selectivity, specificity, linearity, precision, and accuracy by following the SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable relative standard deviation (<20.0%). Recovery was assessed at the limit of quantification level and was observed to fall within the range of 70%-120%, with relative standard deviations below 5.45%. The validated method presented here can be applied to analyze pesticide residues in various other vegetables, fruits, and cereals. It is essential for ongoing monitoring of pesticide residues to ensure public safety.

Nano-metal-organic frameworks as corrosion inhibitors for strengthening anti-corrosion behavior of carbon steel in a sulfuric acid environment: from synthesis to applications.

In order to demonstrate the effect of Nano-metal organic frameworks, [Cu2(CN)4(Ph3Sn) (Pyz2-caH)2] (NMOF1) and [∞3[Cu(CN)2(Me3Sn)(Pyz)]] (NMOF2) as corrosion inhibitors for C-steel in 0.5 M sulfuric acid solutions, the following methods were utilized: mass reduction (MR), potentiodynamic polarization (PDP), and AC electrochemical impedance (EIS). The results of the experiments showed that by increasing the dose of these compounds, the inhibition efficacy (η%) of C-steel corrosion increased and reached 74.4-90% for NMOF2 and NMOF1 at a dose of 25 × 10-6 M, respectively. On the other hand, the η% decreased as the temperature range rose. Parameters for activation and adsorption were determined and discussed. Both NMOF2 and NMOF1 were physically adsorbed on the surface of C-steel and conformed to the Langmuir adsorption isotherm model. The PDP studies revealed that these compounds functioned as mixed type inhibitors, i.e. affecting both metal dissolution and hydrogen evolution reactions. Attenuated Total Reflection Infra-Red (ATR-IR) analysis was carried out to determine the morphology of the inhibited C-steel surface. There is good agreement between the findings of EIS, PDP and MR.

Simultaneous quantification of losartan potassium and its active metabolite, EXP3174, in rabbit plasma by validated HPLC-PDA.

Herein, we report a novel, accurate and cost-effective validated analytical method for the quantification of losartan potassium and its active metabolite, EXP 3174, in rabbit plasma by reversed-phase high-performance liquid chromatography. Valsartan was used as an internal standard. The method was validated as per International Conference on Harmonization guidelines. The analytes were extracted in rabbit plasma using liquid-liquid extraction technique and analyzed at 247 nm after separation through a reverse-phase C18 column. The isocratic mobile phase used is a mixture of acetonitrile, water and glacial acetic acid in the ratio of 60:40:1 v/v/v maintained at pH 3.4. All calibration curves showed a good linear relationship (r > 0.995) within the test range. Precision was evaluated by intra- and interday tests with RSDs <1.91% and accuracy showed validated recoveries of 86.20-101.11%. Based on our results, the developed method features good quantification parameters and can serve as an effective quality control method for the standardization of drugs.

Fetoscopic laser ablation for twin-to-twin transfusion syndrome in Malaysia: A 15-month retrospective cohort review from an emerging centre in South East Asia.

INTRODUCTION: The authors aim to review the early outcomes of fetostopic laser ablation (FLA) to improve outcomes for twin-to-twin transfusion syndrome (TTTS) in an emerging national centre in Malaysia. MATERIALS AND METHODS: This is a retrospective cohort study of 17 monochorionic diamniotic (MCDA) twin pregnancies with severe TTTS treated by FLA over 15 months in a single centre by a single operator after performing simulations. RESULT: The overall survival rate at day 28 after birth for at least one twin was 76% while the dual-twin survival was 64%. The survival rates at day 28 after birth for at least one twin for stages II, III and IV were 90% vs 40% vs 100% (p=0.054) while dual survival rates were 80% vs 0% vs 100% (p=0.05), respectively. The rate of miscarriage was higher with anterior placentation compared to posterior placentation (33% vs 18%, p=0.660). There was one case of recurrent TTTS and no twin anaemia-polycythaemia sequence post-FLA. The fetal medicine unit in Ipoh is the national centre in Malaysia which covers the whole country, including the western coast of the Borneo Island (Sabah, Sarawak and Labuan) accessible only by air travel. All three cases from Borneo Island had resolved TTTS after FLA and dual neonatal survival at day 28 after birth. CONCLUSION: This data from an emerging new fetoscopic laser centre in Malaysia indicates results consistent with the published international learning curve and within the limits of good clinical governance.

Discriminatory of some morphometry and biological aspects of the Cycad blue butterfly, Chilades pandava reared on Cycas and Zamia ornamental palms.

The serious blue butterfly, Chilades pandava -Horsfield, 1829- (Lepidoptera: Lycaenidae) is consider one of the main destructive insect pests for ornamental palms Cycas and Zamia. Biological and morphological measurements were carried out of C. pandava stages reared on Cycas revoluta (Cycadaceae) and Zamia encephalartoides (Zamiaceae). In description details, non-significant variations were recorded between the two gender of cycad blue butterfly in the obtained data, but the male adult was more densely blue or violet than female adult. By the aid of SEM, C. pandava all stages were distinct by long and thick hairs covered all the body. The morphometric characters namely, length, width and venation of wings, body length, forewing, hindwing could be as a guide for taxonomic discrimination. The data showed that the life cycle duration of C. pandava was ranged between 20.64 to 21.7 days. The developmental periods of different C. pandava stages are slightly higher on zamia than cycas palms. This investigation detected that a high survival rate was found on Cycas palms (86%) than the survived rate recording on Zamia palms (82%). In the present study, the described morphometric characters could be used as a guide for taxonomic discrimination of this pest. Consequently, this study added a valuable knowledge about C. pandava to have sound decisions for proposal of its management and conservation in Egypt.

Risk assessment, development and validation of a GC-ECD-based method for the quantification of cypermethrin from green pea.

The present work describes the persistence, dissipation behaviour, half-life, risk assessment and novel gas chromatography method for the residue estimation of cypermethrin in green pea by spraying cypermethrin 10EC at 50 g a.i. ha-1 at fruiting stage followed by another application at a 10 day interval. The sample extraction and cleanup was followed bya modified quick, easy, cheap, effective, rugged, and safe method, and the residues of cypermethrin were determined using a validated gas chromatography method. The initial deposits were found to be 1.21 mg kg-1 following the application of insecticide at 50 g a.i. ha-1 . Cypermethrin residues declined to below the detection limit of 0.05 mg kg-1 after 15 days at the recommended dosage. The half-life of cypermethrin was 2.66 days at 50 g a.i. ha-1 . For risk assessment studies, the waiting period of 15 days is recommended as safe for consumption for the insecticide. The GC-ECD method was validated according to the SANTE guidelines by various analytical parameters including linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable, and can be used for the standardization of pesticides on fruits and vegetables.

Dissipation and gas chromatographic method for the determination of profenofos residues in/on green pea and cucumber.

Herein we report a novel, accurate and cost-effective gas chromatography method for the determination of average deposits of profenofos on green pea and cucumber following good agricultural practices. Additionally the risk assessment, dissipation and waiting period for profenofos were determined. The average initial deposits (2 h after spraying) of profenofos in/on green pea and cucumber were 3.41 and 3.62 mg kg-1 respectively following two applications at a 10 day interval of profenofos 50EC formulation. Profenofos residues on both of the substrates were below the detection limit of 0.05 mg kg-1 after 20 days at the recommended dosage. For risk assessment studies, the 20th day will be safe for consumers for consumption of green peas. The gas chromatography method was validated according to the SANTE guidelines using the various analytical parameters: linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable and can be extended for profenofos-based standardization of pesticide formulations for green pea/cucumber and their use as pesticides.

Patients' Impression of Health Care Providers' Attire in the Emergency Department.

Background The level of patient satisfaction and, ultimately, the assessment of the quality of care are greatly influenced by physicians' capacity to leave a positive impression on patients during provider-patient interactions. The way doctors dress affects how people view their care. There have been few studies on the impact of doctors' attire on patient confidence and trust. The objective of this study is to assess patients' preferences concerning specific cultural attire and its influence on patients' trust, compliance, and perceptions of the quality of care in the emergency department. Methods A cross-sectional study was performed using the survey methodology for patients in emergency departments. Participants completed a written survey after reviewing doctors' portraits in different dress styles. Respondents were asked questions about the importance of the health service providers' attire in the emergency department on the patient's perception. The Statistical Package for Social Sciences version 21 (SPSS; IBM Inc., Armonk, New York) was used to perform the analysis after the data were entered into Microsoft Excel 2016 (Microsoft, Redmond, Washington). The categorical analysis was performed using the Chi-squared test to explore for relationships between the results and various variables. Result A self-administered questionnaire was completed by 395 patients; two responses were excluded for lack of completeness of the answers in it: 33.8%) were males (66.2%) were females (56.7%) were married (73.8%) completed university education (44.8%) were employed and (74.5%) with excellent health conditions. The questionnaire was devoted to the local setting, with pictures of the health care provider (male and female), in different types of doctor's attire included. Respondents overwhelmingly prefer male emergency physicians to dress in medical scrub (50%, p=.0001) and prefer female emergency physicians to dress in a medical scrub with a white coat (68.7%, p=.0001).  Conclusion First impressions based on a physician's appearance serve as the foundation for assumptions about trust, confidence, and competency, particularly in circumstances when patients or family members do not already have a relationship with the provider.

Agro-waste derived compounds (flax and black seed peels): Toxicological effect against the West Nile virus vector, Culex pipiens L. with special reference to GC-MS analysis.

The development of different approaches to use agricultural residues as a source of high value-added products, become a must, especially after the problems emerged due to their accumulation. This contribution demonstrates the potential of agricultural residues, Linuim usitatissium (flax seed) and Nigella sativa (black seed) peels, as raw materials for the production of bioactive products, botanical insecticides, against Cx. pipiens, with deep analysis to their chemical constituents by gas chromatography-mass spectrometry, the larvicidal efficacies of the three crude extracts (methylene chloride, petroleum ether and methanol 70%) from the two plant waste peels were evaluated for the first time against the late third instar larvae of Cx. pipiens. Results indicated different lethal doses in larvae depending on the efficacy of organic solvent used. For both compounds methanol 70% extracts produced the highest dry yield. The most efficient solvent is petroleum ether in case of both flax and Black seed peels. Petroleum ether extract exhibited the highest toxicity against Cx. pipiens with an LC50 of 69.6383 ppm. The same results for black seed indicated that petroleum ether was the most efficient against Cx. pipiens with an LC50 of 40.7748 ppm. The study revealed for the first time the type of phytochemical constituents presents in peels of flax and black seeds using GC-MS analysis which revealed twenty-eight constituents among extracts of flax and black seed peels ranging from to 58.8711% to 99.99% of the total extracts. GC-MS profiling showed that a five constituents, 9-2-Methyl-Z, Z-3, 13 octadecadienol (terpenoid), 9,17-Octadecadienal, (Z)-, Nonanoic acid, 9-oxo-, methyl ester, 9,12-Octadecadienoic acid Z,Z and Octasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl- have insecticidal activity beside many other biological activities as recorded from a variety of botanical extracts. While the constituents like Hexadecanoic acid, methyl ester and cis-9-Hexadecenal, both of them are larvicidal, cis-Vaccenic acid and 9-Oxononanoic acid showing only an insecticidal activity beside Undecanoic acid the mosquito repellent. The other six constituents Linoelaidic acid, Oleic Acid, Z-2-Octadecen-1-ol, 1-Methoxy-3-hydroxymethylheptane, Cis-11,14-Eicosadieonic acid-methyl ester and Heptasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethyl- are constituents of other plant extracts which showed as a whole an insecticidal activity.

Complete atrioventricular block due to ingestion of Visine eye drops.

Visine eye drops are a commonly used topical drug for irritation of the eye. The active component in Visine eye drops is tetrahydrozoline. Tetrahydrozoline is an imidazoline derivative found in several ophthalmic and nasal decongestants. Exposure is common in young children, who unintentionally ingest it, but cases have been rising in the adult population. The main systemic effects are bradycardia and hypotension due to activation of the central alpha-adrenergic receptors. In this case report, a 76-year-old man presents with bradycardia after 24 hours following ingestion of 120 mL of 0.05% tetrahydrozoline (eight bottles of Visine eye drops) in a suicide attempt. His initial ECG demonstrated complete heart block and QT prolongation. Subsequent ECGs showed unremitting first-degree atrioventricular block and QT prolongation. Here, we are presenting the first case of complete heart block following tetrahydrozoline consumption.

Differences in clinical presentation of primary open-angle glaucoma between African and European populations.

PURPOSE: Primary open-angle glaucoma (POAG) has been reported to occur more frequently in Africans, and to follow a more severe course compared to Europeans. We aimed to describe characteristics of POAG presentation and treatment across three ethnic groups from Africa and one from Europe. METHODS: We ascertained 151 POAG patients from South African Coloured (SAC) and 94 South African Black (SAB) ethnicity from a university hospital in South Africa. In Tanzania, 310 patients were recruited from a university hospital and a referral hospital. In the Netherlands, 241 patients of European ancestry were included. All patients were over 35 years old and had undergone an extensive ophthalmic examination. Patients were diagnosed according to the ISGEO criteria. A biogeographic ancestry analysis was performed to estimate the proportion of genetic African ancestry (GAA). RESULTS: The biogeographic ancestry analysis showed that the median proportion of GAA was 97.6% in Tanzanian, 100% in SAB, 34.2% in SAC and 1.5% in Dutch participants. Clinical characteristics at presentation for Tanzanians, SAB, SAC and Dutch participants, respectively: mean age: 63, 57, 66, 70 years (p < 0.001); visual acuity in the worse eye: 1.78, 1.78, 0.3, 0.3 LogMAR (p < 0.001); maximum intraocular pressure of both eyes: 36, 34, 29, 29 mmHg (panova  < 0.001); maximum vertical cup to disc ratio (VCDR) of both eyes: 0.90, 0.90, 0.84, 0.83 (p < 0.001); mean central corneal thickness: 506, 487, 511, 528 µm (p < 0.001). Fourteen percent of Tanzanian patients presented with blindness (<3/60 Snellen) in the better eye in contrast to only 1% in the Dutch. CONCLUSION: In this multi-ethnic comparative study, Sub-Saharan Africans present at a younger age with lower visual acuity, higher IOP, larger VCDR, than SAC and Dutch participants. This indicates the more progressive and destructive course in Sub-Saharan Africans.

Evaluation of Conjunctival Autografting Augmented with Mitomycin C Application versus Ologen Implantation in the Surgical Treatment of Recurrent Pterygium.

OBJECTIVES: To evaluate the safety and efficacy of augmenting conjunctival autografting with intraoperative mitomycin C (MMC) application versus Ologen implantation in the management of recurrent pterygium. MATERIALS AND METHODS: This prospective randomised study included 63 eyes of 63 patients, with recurrent nasal pterygium, who presented to the outpatient clinic of Menoufia University Hospital in Shebin El Kom and Manshiet Soltan from January 2016 to December 2019. Patients were randomly enrolled into two groups. Group A included 32 eyes of 32 patients who underwent conjunctival autografting augmented with the topical application of MMC (0.2 mg/mL), and group B included 31 eyes of 31 patients who underwent conjunctival autografting augmented with Ologen implantation. All the patients underwent follow-up examinations for a period of 24 months. During each visit, a complete ophthalmic examination was performed. Pterygium regrowth of 1 mm or more, over the cornea, was considered a recurrence. RESULTS: In the MMC group, no recurrence was reported during the 24-month follow-up period. In the Ologen implantation group, recurrence was reported in 2 (8%) eyes. The time interval from surgery to recurrence was 5 months in one case and 8 months in the other. No other serious postoperative complications were reported, and there was no statistically significant difference between the groups in this regard. CONCLUSION: Ologen implantation with conjunctival autografting shows promising results in the surgical management of recurrent pterygium with mild non-vision-threatening postoperative complications comparable to that of MMC application with conjunctival autografting. Registration number: ClinicalTrials.govNCT04419038.

Mechanisms Underlying Graft Union Formation and Rootstock Scion Interaction in Horticultural Plants.

Grafting is a common practice for vegetative propagation and trait improvement in horticultural plants. A general prerequisite for successful grafting and long term survival of grafted plants is taxonomic proximity between the root stock and scion. For the success of a grafting operation, rootstock and scion should essentially be closely related. Interaction between the rootstock and scion involves complex physiological-biochemical and molecular mechanisms. Successful graft union formation involves a series of steps viz., lining up of vascular cambium, generation of a wound healing response, callus bridge formation, followed by vascular cambium formation and subsequent formation of the secondary xylem and phloem. For grafted trees compatibility between the rootstock/scion is the most essential factor for their better performance and longevity. Graft incompatibility occurs on account of a number of factors including of unfavorable physiological responses across the graft union, transmission of virus or phytoplasma and anatomical deformities of vascular tissue at the graft junction. In order to avoid the incompatibility problems, it is important to predict the same at an early stage. Phytohormones, especially auxins regulate key events in graft union formation between the rootstock and scion, while others function to facilitate the signaling pathways. Transport of macro as well as micro molecules across long distances results in phenotypic variation shown by grafted plants, therefore grafting can be used to determine the pattern and rate of recurrence of this transport. A better understanding of rootstock scion interactions, endogenous growth substances, soil or climatic factors needs to be studied, which would facilitate efficient selection and use of rootstocks in the future. Protein, hormones, mRNA and small RNA transport across the junction is currently emerging as an important mechanism which controls the stock/scion communication and simultaneously may play a crucial role in understanding the physiology of grafting more precisely. This review provides an understanding of the physiological, biochemical and molecular basis underlying grafting with special reference to horticultural plants.

Effect of Fluoride Concentration in Drinking Water on Dental Fluorosis in Southwest Saudi Arabia.

This study was intended to evaluate the fluoride concentration in drinking water and its effect on dental fluorosis in Southwest Saudi Arabia. Water samples were gathered rom wells, filtration plants and commercial brands (bottled water) in distinct urban and rural areas of Asir region of the Kingdom of Saudi Arabia (KSA). Overall, 63 water samples were collected from 12 locations and 9 brands of bottled water. ExStik® FL700Fluoridemeter was used in the analysis of water samples for fluoride levels. The total number of screened patients for dental fluorosis, aged between 9 and 50 years, was 1150; among them, 609 were males and 541 were females. Dean's index criteria were used to examine the patients for dental fluorosis. The results revealed that fluoride levels varied between 0.03 and 3.8 ppm. People who drank well water displayed increased fluoride levels (>0.81 ppm). The prevalence of dental fluorosis was established to be 20.43% among the total number of examined patients. The findings of this study show very mild to moderate dental fluorosis prevail among the patients who consume well water in the Asir region.

Assessment of absorbed dose of gamma rays using the simultaneous determination of inactive hemoglobin derivatives as a biological dosimeter.

Biological dosimetry based on sulfhemoglobin (SHb), methemoglobin (MetHb), and carboxyhemoglobin (HbCO) levels was evaluated. SHb, MetHb and HbCO levels were estimated in erythrocytes of mice irradiated by γ rays from a 60Co source using the method of multi-component spectrophotometric analysis developed recently. In this method, absorption measurements of diluted aqueous Hb-solution were made at λ = 500, 569, 577 and 620 nm, and using the mathematical formulas based on multi-component spectrophotometric analysis and the mathematical Gaussian elimination method for matrix calculation, the concentrations of various Hb-derivatives and total Hb in mice blood were estimated. The dose range of γ rays was from 0.5 to 8 Gy and the dose rate was 0.5 Gy min-1. Among all Hb-derivatives, MetHb, SHb and HbCO demonstrated an unambiguous dose-dependent response. For SHb and MetHb, the detection limits were about 0.5 Gy and 1 Gy, respectively. After irradiation, high levels of MetHb, SHb and HbCO persisted for at least 10 days, and the maximal increase of MetHb, SHb and HbCO occurred up to 24 h following γ irradiation. The use of this "MetHb + SHb + HbCO"-derivatives-based absorbed dose relationship showed a high accuracy. It is concluded that simultaneous determination of MetHb, SHb and HbCO, by multi-component spectrophotometry provides a quick, simple, sensitive, accurate, stable and inexpensive biological indicator for the early assessment of the absorbed dose in mice.

The hidden hand is perceived closer to midline.

Whether visible or not, knowing the location of our hands is fundamental to how we perceive ourselves and interact with our environment. The present study investigated perceived hand location in the absence of vision in 30 participants. Their right index finger was placed 10, 20 or 30 cm away on either side of the body midline, with and without their left index finger placed 10 cm to the left of the right index. On average, at each position, participants perceived their right hand closer to the body midline than it actually was. This underestimation increased linearly with increased distance of the hand from body midline [slope 0.77 (0.74 to 0.81), mean (95% CI)]. Participants made smaller errors in perceived hand location when the right hand was in the contralateral workspace [mean difference 2.13 cm (1.57 to 2.69)]. Presence of the left hand on the support surface had little or no effect on perceived location of the right hand [mean difference [Formula: see text] cm ([Formula: see text] to 0.02)]. Overall, participants made systematic perceptual errors immediately after hand placement. The magnitude of these errors grew linearly as the hand got further away from the body midline. Because of their magnitude, these errors may contribute to errors in motor planning when visual feedback is not available. Also, these errors are important for studies in which perceived hand location is assessed after some time, for example, when studying illusions of body ownership and proprioceptive drift.

Soybean isoflavone affects in rabbits: Effects on metabolism, antioxidant capacity, hormonal balance and reproductive performance.

Though soybean isoflavones (SBI) have pharmaceutical properties, the compounds also have endocrine disrupting activities that may adversely affect fertility of mammals. The effects of SBI on metabolism, antioxidant capacity, hormonal balance and reproductive performance of male rabbits were investigated. Adult male rabbits (n = 21) fed an isoflavone-free diet were orally treated with 0 (control; CON), 5 (small; LSBI) or 20 (large; HSBI) mg of SBI/kg body weight/day for 12 weeks. Both SBI doses resulted in lesser blood plasma total protein concentrations, while there were no effects on glucose and cholesterol concentrations compared to CON. The HSBI-treated males had the greatest (P < 0.05) blood plasma total antioxidant capacity and least malondialdehyde. Treatment with both SBI doses induced a 43% increase in triiodothyronine concentrations (P < 0.05) and 82% in reaction times (P < 0.001), while decreased sperm concentrations (P = 0.01) and blood plasma testosterone concentrations (P = 0.017) 26% and 19%, respectively. The total functional sperm fraction was less (P < 0.05) in the HSBI group; however, there was no effect of the LSBI treatment as compared to values for the CON group. The kindling rates of females mated to HSBI-treated males tended to be less (P = 0.081) than those of does mated with LSBI or CON males. In conclusion, only the HSBI treatment improved antioxidant status; whereas, treatment with both LSBI and HSBI doses induced a hormonal imbalance which led to an impaired testis function indicating the sensitivity of the adult male reproductive system to SBI actions.

Effects of horizontal distance and limb crossing on perceived hand spacing and ownership: Differential sensory processing across hand configurations.

We have previously shown that, with the hands apart vertically, passively grasping an artificial finger induces a sense of ownership over the artificial finger and coming-together of the hands. The present study investigated this grasp illusion in the horizontal plane. Thirty healthy participants were tested in two conditions (grasp and no grasp) with their hands at different distances apart, either crossed or uncrossed. After 3 min, participants reported perceived spacing between index fingers, perceived index finger location, and, for the grasp condition, perceived ownership over the artificial finger. On average, there was no ownership at any of the hand configurations. With the hands uncrossed 7.5, 15 or 24 cm apart, there was no difference in perceived spacing between the grasp and no grasp conditions. With the hands crossed and 15 cm apart, perceived spacing between index fingers was 3.2 cm [0.7 to 5.7] (mean [95% CI]) smaller during the grasp condition compared to no grasp. Therefore, compared to when the hands are vertically separated, there is an almost complete lack of a grasp illusion in the horizontal plane which indicates the brain may process sensory inputs from the hands differently based on whether the hands are horizontally or vertically apart.

Genome-wide association study of primary open-angle glaucoma in continental and admixed African populations.

Primary open angle glaucoma (POAG) is a complex disease with a major genetic contribution. Its prevalence varies greatly among ethnic groups, and is up to five times more frequent in black African populations compared to Europeans. So far, worldwide efforts to elucidate the genetic complexity of POAG in African populations has been limited. We conducted a genome-wide association study in 1113 POAG cases and 1826 controls from Tanzanian, South African and African American study samples. Apart from confirming evidence of association at TXNRD2 (rs16984299; OR[T] 1.20; P = 0.003), we found that a genetic risk score combining the effects of the 15 previously reported POAG loci was significantly associated with POAG in our samples (OR 1.56; 95% CI 1.26-1.93; P = 4.79 × 10-5). By genome-wide association testing we identified a novel candidate locus, rs141186647, harboring EXOC4 (OR[A] 0.48; P = 3.75 × 10-8), a gene transcribing a component of the exocyst complex involved in vesicle transport. The low frequency and high degree of genetic heterogeneity at this region hampered validation of this finding in predominantly West-African replication sets. Our results suggest that established genetic risk factors play a role in African POAG, however, they do not explain the higher disease load. The high heterogeneity within Africans remains a challenge to identify the genetic commonalities for POAG in this ethnicity, and demands studies of extremely large size.