bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of bone mineral density, Vitamin D, and serum calcium in intracranial aneurysm
Authors: Sharma Achal , Sharma Jitesh
Published: September 2020

Aims: The objective of this study is to understand the association between bone mineral density (BMD), serum calcium, and Vitamin D in s (IA) patients. Subjects and Methods: A total of 100 patients with IA diagnosed at the department of neurosurgery between January 2019 and December 2019 were reviewed and analyzed in this study. Computed tomography angiography was used to confirm and locate the site of aneurysms. BMD, serum calcium, and Vitamin D levels were measured. Statistical Analysis Used: Linear or logistic regression statistical models were applied to found the association between BMD and IA size. To confirm the statistical significance, P < 0.05 (twos-tailed) was considered as statistically significant. Results: Of the studied 100 patients, 61 patients were female and 39 were male. According to the age group, patients were divided into five categories: below 30, 31–40, 41–50, 51–60, and ≥60 years. The most common site of aneurysm observed to be the anterior communicating artery (Acom); 39.25% of the patients had Acom aneurysm followed by the middle cerebral artery (18.69%). This clearly shows that the occurrence of aneurysm is more prominent in anterior circulation as compared to posterior circulation. The results showed that there is a negative linear correlation between BMD and size of aneurysm (P = 0.00043, r =−0.12). Sex-specific analysis showed that females have lower mean BMD value as compared to males (i.e., females 0.785 ± 0.13; males 0.887 ± 0.13; P = 0.0003). We also found that the multiplicity of IAs also shows an association with BMD (i.e. mean BMD: 0.825 ± 0.14, whereas BMD of patients with multiple aneurysms was 0.747 ± 0.08; P = 0.05). Of 100 patients, 66 were observed calcium deficient (normal range: 8.8–10.2 mg/dl). The obtained mean value of calcium was 8.56 ± 0.859 standard deviation (SD), i.e., below the normal range of calcium. In the case of Vitamin D, 85% of the patients were observed Vitamin D deficient, whereas 14 patients showed Vitamin D insufficiency and merely 1 patient has Vitamin D sufficiency. The mean 25-hydroxy Vitamin D level obtained in our study was 14.57 ± 5.60 (SD), which is considered as Vitamin D deficiency. Conclusions: The size and multiplicity of IA can be associated with BMD, calcium, and Vitamin D. The results from the research provide evidence of common pathophysiology between the development of IA and these factors.
Endoscopic excision of intraventricular neurocysticercosis cyst with an angiocatheter: A retrospective analysis
Authors: Aggarwal Varun , Krishna Gopal , Singh Ishwar
Published: September 2020

Introduction: An intraventricular cysticercus cyst is observed in 7%–30% patients of neurocysticercosis (NCC). Apart from causing arachnoiditis, intraventricular NCC (IVNCC) can cause sudden death due to acute episodes of hydrocephalus. Various treatment modalities available are external cerebrospinal fluid (CSF) diversion, microsurgical removal, and endoscopic management. There is no consensus regarding the optimal surgical treatment strategy. We are presenting our experience by doing a retrospective analysis of 26 patients having endoscopic removal of IVNCC with a rigid endoscope and angiocatheter. Aim: The aim of this study is to evaluate the results of neuroendoscopy in restoring the CSF pathway and removal of the cyst in patients of IVNCC. Materials and Methods: Retrospective analysis of clinical record and follow-up of 26 patients of IVNCC who were treated endoscopically between 2010 and 2018 was done. The diagnosis of IVNCC was made based on contrast enhanced magnetic resonance imaging of the brain. Transcranial endoscopy with 0° endoscope was performed through the frontal burr hole. Third ventriculostomy and removal of the cysticercus cyst with angiocatheter were the procedures done. Results: The success rate of intraventricular cyst excision, whether complete or partial, was 100% (14/14) in the third ventricular cyst, 62.5% (5/8) in the fourth ventricular cyst and 100% (4/4) in the lateral ventricular cyst. The overall success rate of cyst excision by endoscopy was 88.46%. The overall successful CSF flow pathway was established in 88.46% cases. The mean duration of follow-up was 44 months, and all the patients were found symptom free in the follow-up period. Conclusion: Neuroendoscopy, being a single burr hole technique successfully providing internal CSF diversion and cyst removal, is the treatment modality of choice for IVNCC.
Primary intracranial squamous cell carcinoma with a fatal course
Authors: Pisano Patrizia , Lombardi Francesco , Bongetta Daniele , La Rocca Giuseppe , Della Pepa Giuseppe , Zoia Cesare
Published: September 2020

Intracranial squamous cell carcinomas (SCCs) are extremely rare. They can be primary or represent a degeneration of an epidermoid cyst (EC). We report the case of a patient operated, with an endoscopic transnasal approach, for a primary intracranial SCC. The optimal management for patients with primary intracranial SCC or ECs which have undergone malignant degeneration has yet to be identified.
The onset and recovery timeline of visual photosensitivity following mild traumatic brain injury with special focus on habitual digital device screens users
Authors: Das Matuli , Das Narendra
Published: September 2020

Primary Objective: Visual photosensitivity following mild traumatic brain injury (mTBI) can cause mild discomfort to significant pain and can affect a person's ability to lead a regular life and perform normal activities. The purpose of the present study is twofold: (1) To determine the recovery pattern of visual photosensitivity following mTBI and (2) to find out whether the onset of visual photosensitivity and its recovery pattern is any different among habitual screen users (HSU) (chronic exposure to digital device screens). Materials and Methods: This study was a hospital-based prospective, analytical, observational study. The study period was from July 2017 to March 2019. All the mTBI patients with visual photosensitivity who fulfilled the inclusion Criteria were followed up for 1 year to capture their recovery profile. Results: In 60% of the patients, the time of appearance of visual photosensitivity was at around 3 month's post-mTBI. Nearly 66.6% of patients suffering from visual photosensitivity following mTBI recovered within 3 months following the onset of their symptoms. The symptoms of visual photosensitivity appeared earlier among the HSU as compared to nonscreen users (P = 0.0039). The recovery from the symptoms of visual photosensitivity following mTBI is delayed in HSU (P = 0.0028). The patients in whom the symptoms of visual photosensitivity persisted beyond a year were predominantly HSU (P = 0.0062). Conclusions: The present study has given a new insight on the timeline of recovery for the patients with visual photosensitivity following mTBI. To the best of our knowledge, this is the only study which has shown how chronic exposure to blue light from digital device screens can affect the recovery of visual symptoms such as visual photosensitivity following mTBI.
Surgery in high-grade insular tumors: Oncological and seizure outcomes from 41 consecutive patients
Authors: Khatri Deepak , Das Kuntal , Gosal Jaskaran , Attri Gagandeep , Singh Amanjot , Bhaisora Kamlesh , Mehrotra Anant , Sardhara Jayesh , Verma Pawan , Srivastava Arun , Jaiswal Awadhesh , Behari Sanjay
Published: September 2020

Background: Insular high-grade gliomas are uncommon and constitute approximately 10% of all intracranial high-grade gliomas. Several publications in the recent years have thrown substantial light in the understanding of insular low-grade gliomas. However, there is a paucity of information concerning the spectrum of high-grade lesions affecting the insula, the mode of presentation vis-à -vis low-grade gliomas, and the survival rates to modern therapy. Aims and Objectives: We aim to highlight various clinical patterns, histo-pathological spectrum and the survival rates in patients with high-grade insular lesions. Also, we explore the factors that govern favourable outcomes. Materials and Methods: A retrospective study of 41 patients operated for high-grade insular tumors at our institute between March 2010 to December 2018 was done to evaluate the clinico-radiological features, surgical nuances, survival rates and seizure outcomes. Results: Raised intracranial pressure was the most frequent clinical presentation (n=28/41, 68.3%). Nearly 60% of the patients (n=25) had involvement of all four Berger-Sanai zones. The high-grade tumors encountered in our series were: glioblastoma (n=15), gliosarcoma (n=3), and embryonal tumor, not otherwise specified in 3 patients, while 21 patients had grade 3 astrocytoma. 33 out of 41 patients (80.5%) in our study showed excellent seizure control (ILAE grade 1A) at follow-up. Clinical presentation with seizures (P = 0.01, HR=0.3), WHO grade IV histopathology (P = 0.04, HR=3.7) and development of recurrence (P = 0.05, HR=5.5) were found to be independent predictors of OS. Conclusion: Insular high-grade gliomas are commoner than thought and nearly half of these are grade IV tumors (51%). A presentation with seizures may indicate precursor low-grade gliomas and portend a better survival. A maximum “safe” surgical resection, keeping the postoperative quality of life in mind, should be the goal.
Outcome and prognostic factors of primary central nervous system lymphoma in Southern Thailand
Authors: Sopittapan Thanya , Tunthanathip Thara , Kaewborisutsakul Anukoon
Published: September 2020

Context: Primary central nervous system lymphoma (PCNSL) is an uncommon type of brain tumor that has an aggressive disease course. Its outcomes, including factor-related outcomes, are therefore not well established in our country. Aims: This study aims to investigate the outcome and prognostic factors in PCNSL patients at our institute. Settings and Design: Retrospective study in a single university hospital. Subjects and Methods: We reviewed consecutive cases of newly diagnosed PCNSL at Prince of Songkla University from 2005 to 2018. The data were collected to evaluate the treatment outcomes and prognostic factors. Statistical Analysis Used: The Kaplan–Meier method for survival analysis, and Cox regression for variable analysis. Results: Eighty-seven patients met the inclusion criteria. Patients were predominantly male, and their mean age was 58.8 ± 11.2 years. Only four patients were infected with HIV. Motor weakness was the most common presentation, and neuroimaging revealed multiple lesions in 56.3% of patients. The patients were divided into four groups according to treatment modality: palliative treatment, whole-brain radiotherapy (WBRT) alone, chemotherapy (CMT) alone, and combined WBRT and CMT groups. The median overall survival was 7 months. The 1-, 2-, and 5-year survival rates were 29%, 21.5%, and 4.6%, respectively. The age of >60 years was a significant poor prognostic factor. In addition, patients who received combined treatment exhibited the highest survival rate. Conclusions: PCNSL has a low survival rate, even in the present era. Older age is the most substantial factor associated with unfavorable outcomes. The most effective treatment is combined with WBRT and CMT.
Collision tumors: A rare case report
Authors: Velho Vernon , Sadhwani Nidhisha , Bhide Anuj
Published: September 2020

The presence of collision tumors without any evidence of phacomatoses, genetic syndromes, or any history of previous radiation to the brain is extremely rare. We report a case with two diverse primaries, a tentorial meningioma and a colloid cyst found in the same patient occurring in the absence of these conditions. To the best of our knowledge, a single case of a colloid cyst and meningioma found together in the same patient has been reported till date. In such cases, the surgical dilemma as to which tumor to operate first has been addressed in our case report.
Randomized trial to compare plasma glucose trends in patients undergoing surgery for supratentorial gliomas under maintenance of sevoflurane, desflurane, and propofol
Authors: Haldar Rudrashish , Kannaujia Ashish , Verma Ruchi , Mondal Himel , Gupta Devendra , Srivastava Shashi , Agarwal Anil
Published: September 2020

Background: Anesthetic agents influence the glycemic response by affecting the neuroendocrine surgical response or directly modifying pancreatic insulin release. Due to chances of neuronal damage, intraoperative hyperglycemia and hypoglycemia both are detrimental for patients undergoing neurosurgeries. Inhalational (sevoflurane and desflurane) and intravenous (propofol) agents have been found to raise intraoperative glucose levels in nonneurological surgeries. Aim: We aimed to compare the intraoperative glucose levels in supratentorial glioma surgeries under the maintenance of three anesthetic agents such as sevoflurane, desflurane, and propofol. Materials and Methods: This randomized trial was conducted with 90 nondiabetic adults with supratentorial glioma. Thirty patients were allocated randomly to the three groups receiving sevoflurane, desflurane, and propofol. Baseline and hourly plasma glucose levels were recorded. Postoperatively, the time required to achieve an Aldrete score of 9 and complications were assessed. Results: Baseline plasma glucose levels were 111.23 ± 11.67, 109.47 ± 19.75, and 111.7 ± 13.88 mg/dL (P = 0.84) in sevoflurance, desflurane, and propofol group, respectively. All of them showed an elevation of plasma glucose in relation to the time of surgery with variable trends. In the 4th and 5th h, the elevations in the inhalational groups (sevoflurane and desflurane) were significantly higher than the propofol group (P = 0.003 and 0.002, respectively). The time for achieving Aldrete's score of 9 was higher in the propofol group (P < 0.0001). No differences were observed in the duration of hospital stay or complications. Conclusions: Maintenance of anesthesia in nondiabetic patients showed clinically modest rise of plasma glucose which is higher in patients under sevoflurane and desflurane than under propofol. However, the immediate recovery was faster with inhalational agents compared to propofol-based anesthesia.
A novel technique for mitigation of the ledge effect caused by the use of a large-lumen catheter during neurointervention: Beanstalk method
Authors: Ohshima Tomotaka , Miyachi Shigeru
Published: September 2020

Navigating a large-caliber catheter into the intracranial artery may generate a “ledge effect,” which disturbs successful neurointervention. Particularly, navigation of a large-lumen aspiration catheter is often required to achieve fast recanalization in acute ischemic stroke cases. Occasionally, the aspirator cannot be passed through the ophthalmic artery origin because of the ledge effect. Here, we report a new technique for mitigation of the ledge effect that involves the use of double micro-guidewires (MGWs). We refer to this technique as the “beanstalk method.” We evaluated the efficacy of our idea using a silicon vascular model. Two 0.014” MGWs are used for navigation of a 0.068” aspirator. After one guidewire is navigated to the distal portion, another MGW is advanced along with the former guidewire, in a spiral fashion, similar to the growth of a beanstalk. The aspirator can then pass with the coaxial double-guidewire, although there is a severe gap in the vessel. We performed an in vitro study to demonstrate the effectiveness of the beanstalk method. The beanstalk method was very useful, even under challenging conditions that did not allow for passage of a conventional coaxial catheter or buddy-wire. The beanstalk method effectively decreases the ledge effect because of the shape of the two wires just ahead of the catheter, which contrasts with the hardness of the spiral wires. In cases involving challenging vasculature, the beanstalk method achieves smoother catheter navigation than the conventional coaxial method or buddy-wire technique.
Success rate of simple coil embolization in wide-neck aneurysm with aneurysmal shoulder
Authors: Decharin Payothorn , Churojana Anchalee , Aurboonyawat Thaweesak , Chankaew Ekawut , Songsaeng Dittapong , Sangpetngam Boonrerk , Withayasuk Pattarawit
Published: September 2020

Background and Objective: Wide-necked intracranial aneurysm (WIA) is one of the challenging diseases for neuro-interventionist to treat by simple coiling technique. The purpose of this study is to identify the morphology associated with successful simple coil embolization in wide neck aneurysm patients. Materials and Methods: Between January 2002 and August 2018, 102 patients with total 115 ruptured or unruptured WIA which received endovascular treatment were retrospective reviewed. Data were analyzed including demographics, aneurysm morphology, endovascular technique, angiographic outcome, complication, regrowth, and retreatment rate. Results: The mean age of patients was 61.6 years with female predominant (72.5%). Ruptured WIA was diagnosed in 71 patients (61.7%). Majority of aneurysms were located in an anterior circulation which were 74 cases (64.3%), mainly paraclinoid aneurysm (30/115). Endovascular treatment was successful in 113 cases (98.3%) which can be mainly divided into simple coil embolization 50 cases (43.5%), balloon-assisted coil embolization 26 cases (22.6%), and stent-assisted coil embolization 32 cases (27.8%). Complete, subtotal, and incomplete occlusion of WIA was achieved in 32 cases (27.8%), 62 cases (53.9%), and 18 cases (15.7%), respectively. There was 9.6% complication occurred. Regrowth and retreatment were found 20% and 15.7%, respectively. Conclusion: WIA with two-sided aneurysmal shoulder or neck width <3.6 mm. are significantly associated with successful coil embolization using simple coiling technique.
Comparison of ketofol (combination of ketamine and propofol) and propofol anesthesia in aneurysmal clipping surgery: A prospective randomized control trial
Authors: Bhardwaj Ajit , Panda Nidhi , Chauhan Rajeev , Bloria Summit , Bharti Neerja , Bhagat Hemant , Bhaire Vishwanath , Luthra Ankur , Chhabra Rajesh , Mahajan Shalvi
Published: September 2020

Background: The maintenance of hemodynamic stability is of pivotal importance in aneurysm surgeries. While administering anesthesia in these patients, the fluctuations in blood pressure may directly affect transmural pressure, thereby precipitating rupture of aneurysm and various other associated complications. We aimed to compare the effects of ketofol with propofol alone when used as an induction and maintenance anesthetic agent during surgical clipping of intracranial aneurysms. Materials and Methods: Forty adult, good-grade aneurysmal subarachnoid hemorrhage patients posted for aneurysm neck clipping were included in the study. The patients were randomized into two groups. One group received a combination of ketamine and propofol (1:5 ratio) and the other group received propofol for induction and maintenance of anesthesia. Intraoperative hemodynamic stability, intraventricular pressure, and quality of brain relaxation were studied in both the groups. Results: The patients were comparable with respect to demographic profile, Hunt and Hess grade, world federation of neurological surgeons (WFNS) grade, Fisher grade, duration of anesthesia, duration of surgery, optic nerve sheath diameter, and baseline hemoglobin. Intraoperative hemodynamics were better maintained in the ketofol group during induction, with only 15% of patients having >20% fall in mean arterial pressure (from baseline) intraoperatively, compared to 45% of patients receiving propofol alone (P = 0.038). The mean intraventricular pressure values in both the groups were in the normal range and the quality of brain relaxation was similar, with no significant difference (P > 0.05). Conclusion: Ketofol combination (1:5) as compared to propofol alone provides better hemodynamic stability on induction as well as maintenance anesthesia without causing an increase in intracranial pressure. Effect of ketofol on cerebral oxygenation and quality of emergence need to be evaluated further by larger multicentric, randomized control trials.
Comparison of propofol and sevoflurane on cerebral oxygenation using juglar venous oximetery (SjVo2) in patients undergoing surgery for traumatic brain injury
Authors: Chauhan Rajeev , Panda Nidhi , Bhagat Hemant , Bharti Neerja , Luthra Ankur , Soni Shiv , Kaloria Narender , Salunke Praveen , Bhaire Vishwanath , Bloria Summit
Published: September 2020

Background: Traumatic brain injury (TBI) induces major insult to the normal cerebral physiology. The anesthetic agents may infrequently produce deleterious effects and further aggravate damage to the injured brain. This study was conducted to evaluate the effects of propofol and sevoflurane on cerebral oxygenation, brain relaxation, systemic hemodynamic parameters and levels of interleukin-6 (IL-6) in patients with severe TBI undergoing decompressive craniectomy. Methods: A prospective randomized comparative study was conducted on 42 patients undergoing surgery for severe TBI. Patients were randomized into two groups, Group P received propofol and Group S received sevoflurane for maintenance of anesthesia. All patients were induced with fentanyl, propofol, and vecuronium. The effect of these agents on cerebral oxygenation was assessed by jugular venous oxygen saturation (SjVO2). Hemodynamic changes and quality of intraoperative brain relaxation were also assessed. The serum levels of IL-6 were quantitated using enzyme-linked immunosorbent assay technique. Results: SjVO2 values were comparable and mean arterial pressure (MAP) was found to be significantly lower in Group P as compared to those in Group S (P < 0.05). Brain relaxation scores were comparable between the groups. The level of IL-6 decreased significantly at the end of surgery compared to baseline in patients receiving sevoflurane (P = 0.040). Conclusions: Cerebral oxygenation measured by SjVO2 was comparable when anesthesia was maintained with propofol or sevoflurane. However, significant reduction in MAP by propofol needs attention in patients with severe TBI. The decrease in IL-6 level reflects anti-inflammatory effect and probable neuroprotective potential of propofol and sevoflurane.
Rare cases of contrast-induced encephalopathies
Authors: Nakao Kazutaka , Joshi Girish , Hirose Yuichi , Tanaka Riki , Yamada Yasuhiro , Miyatini Kyosuke , Thavara Binoy , Kawase Tsukasa , Kato Yoko
Published: September 2020

Cortical blindness (CB) due to contrast-induced encephalopathy is a rare complication in endovascular procedure. Although exact mechanism is not known, disruption of blood–brain barrier (BBB) by contrast agent is supposed to be caused. We report two cases of contrast-induced encephalopathies after coil embolization of unruptured aneurysm. A 68-year-old woman with unruptured basilar artery aneurysm was treated with endovascular stent-assisted coil embolization. The procedure was successfully accomplished within 172 min using about 160 ml of contrast medium (iopamidol). However, she manifested with CB 3 h after the procedure and seizure on the next day. Immediate computed tomography revealed the cortical enhancement in both occipital lobes. Diffusion-weighted imaging–magnetic resonance imaging and fluid-attenuated inversion recovery sequence 1 day after the procedure revealed edema in both occipital lobes with no findings of ischemia or hyperperfusion. Electroencephalography showed sharp and slow waves in both occipital lobes. She required endotracheal intubation on day 2 to maintain airways and breathing. Her sensorium improved 4 days after the procedure with administration of steroid and anticonvulsant. She was extubated on day 4 after the procedure. She was discharged with persisting CB as a sequel.
A rare case of giant intradiploeic epidermal cyst of the frontal bone with intracranial extension
Authors: Mohan Akhil , Unni Chandramohan , Kannoth Prakasan , Parambil Rajeev
Published: September 2020

Calvarial intradiploeic epidermal cyst are very rare neoplasms which can have intracranial extension. These cysts can attain a large size and can cause lytic destruction of the calvarium resembling malignancy. Since these lesions are benign complete excision is curative. We report the case of a 77-year-old male patient who presented with a large swelling on the forehead. Computed tomography and magnetic resonance imaging showed an expansile lytic lesion with intracranial extension. Complete excision of the lesion with cranioplasty was done. Histopathology was consistent with the epidermal cyst. These cysts attaining gigantic proportions are very few in literature.
Intracranial, extradural, hemangiopericytoma in a neonate
Authors: Pati Akash , Mahalik Santosh , Mitra Suvradeep , Naik Suprava , Das Kanishka
Published: September 2020

Intracranial infantile hemangiopericytoma (HPC) is a rare, sparsely documented neoplasm with a relatively favorable prognosis than its adult counterpart. We describe a neonatal extradural, intracranial, infantile HPC managed with near-total excision.
The Effectiveness of a Patakara Device in Improving Oral Function and Quality of Life in People with Intellectual Disabilities
Authors: Tsai Cheng-Hung , Chou Yu-Ching , Lin Jin-Ding , Chen Gunng-Shinng
Published: September 2020

Background:

Better labial closure strength (LCS) may improve eating, swallowing, and quality of life. Patakara is an efficient device to enhance lip strength. In this study, we analyzed differences in LCS and quality of life between before and after training with Patakara in people with intellectual disabilities.

Methods:

We recruited twenty participants with intellectual disabilities who had poor eating status, lower LCS, or poor oral hygiene status. These participants performed training using Patakara three times a day (3 min each time for five times/week) for 3 months. Oral examination was performed twice, and structural questionnaires and lip force measurements were performed five times. Cheek temperature was also recorded.

Results:

The maximum value of lip force showed a significant increase during the 3-month training period. In addition, the proportion of participants who kept food in the mouth for a long time when eating significantly reduced. Moreover, the physical functioning and mental health scores of SF-36 showed a significant increase.

Conclusions:

Patakara training effectively increased lip muscle strength and improved dietary function. Nevertheless, further studies with a longer training duration to investigate the long-term effects of Patakara training are needed.
Lineability, continuity, and antiderivatives in the non-Archimedean setting
Authors: Khodabandehlou J. , Maghsoudi S. , Seoane-Sepúlveda J. B.
Published: September 2020

This work focuses on the ongoing research of lineability (the search for large linear structures within certain non-linear sets) in non-Archimedean frameworks. Among several other results, we show that there exist large linear structures inside each of the following sets: (i) functions with a fixed closed subset of continuity, (ii) all continuous functions that are not Darboux continuous (or vice versa), (iii) all functions whose Dieudonné integral does not behave as an antiderivative, and (iv) functions with finite range and having antiderivative.
Quantification and Removal of Trichloromethane in Chlorinated Water Using Coconut Shell Activated Carbon
Authors: Okoya A. A. , Akinola O. E. , Adegbaju O. S. , Akinyele A. B. , Amuda O. S.
Published: September 2020

Commercially, available activated carbon (CAC) and coconut shell activated carbon (CSAC) were used in the adsorption of Trichloromethane (TCM) from disinfected water using the optimum conditions (concentration, dosage, pH and time) obtained. Concentrations of TCM were determined using GC-MS. Physicochemical parameters of CSAC were investigated. The CSAC gave percentage carbon yield (86.72±1.41), surface area 1200 m2/g and CHNS/O Elemental Analyzer gave elemental Carbon of 60.08% as the highest of the elements in the char. A pore structure dispersed on the CSAC surface was observed. Best conditions for CSAC were: 1.4 × 104μg/l TCM, 5.0 pH, 0.8 g absorbent within 30 minutes. The data fitted Freundlich than Langmuir model (R2 of 0.9977 and 0.9232, respectively). Percentage removal of TCM for CAC and CSAC was 98.3±1.55 and 96.7±1.27, respectively for the water sample. Results indicated that CSAC was efficient for removal of TCM present in water and could be used as alternative for CAC in water treatment.
Stock Market Efficiency in the Time of COVID-19: Evidence from Industry Stock Returns
Authors: Lalwani Vaibhav , Meshram Vedprakash Vasantrao
Published: September 2020

Using industry portfolios as test assets and a battery of statistical tests, we study if the informational efficiency of stock prices has declined after the COVID-19 crisis began. The results suggest that the predictability of stock returns in some industries has increased during the COVID-19 period. Markets appear to have become less informationally efficient during the COVID-19 crisis.

JEL Classification Code: C58, G01, G10, G14.
Aves silvestres criadas em cativeiro na cidade de Eirunepé, médio rio Juruá, sudoeste da Amazônia brasileira
Authors: De Oliveira Miberly Cavalcante , Pedroza Diego
Published: September 2020

Neste estudo, realizamos um levantamento de aves silvestres em cativeiro e o modo de manutenção (criação) desses animais na cidade de Eirunepé, Amazonas, Brasil. Coletamos os dados de duas formas: sorteio de ruas a serem amostradas e indicação de criadores por informantes. Registramos 142 aves, pertencentes a 15 espécies de Psittacidae, Rallidae e Thraupidae. As três espécies com os maiores percentuais de registro foram Sporophila angolensis (34,5%, n = 49), S. lineola (33,8%, n = 48) e Amazona festiva (9,2%, n = 13). Os modos de criação registrados foram: gaiolas (84,51%, n = 120), soltas nas imediações da residência (9,15%, n = 13) e amarradas pelo tarso (6,34%, n = 9). Das espécies registradas, apenas S. cf. maximiliani está criticamente ameaçada de extinção. Concluímos que a manutenção de aves cativas em Eirunepé está, em grande parte, concentrada em passeriformes e que as finalidades da criação podem ser para estimação, uso em disputas de canto e rinhas ou reabilitação e, além disso, a manutenção das aves pode variar de acordo com o tamanho dos indivíduos. É fundamental que os criadores tenham conhecimento sobre as maneiras adequadas de criação e de como obter aves silvestres de maneira legal no Brasil.
Síntese verde de nanopartículas de prata intermediada por fungo anamórfico e eficácia antibacteriana e antifúngica
Authors: Gomes Dib Mady Diniz , Durán Nelson , Seabra Amedea Barozzi , Silva Larissa De Paiva , Prado Fabiano Brito , Silva Taciana De Amorim , Teixeira Maria Francisca Simas
Published: September 2020

O objetivo deste estudo foi investigar o efeito do pH, da temperatura e da concentração de nitrato de prata (AgNO3) na síntese de nanopartículas de prata (AgNPs) por Aspergillus flavo-furcatis e avaliar o respectivo potencial antimicrobiano. Um experimento fatorial 2³ foi realizado para avaliar o efeito das condições físico-químicas na síntese de AgNPs. A caracterização das AgNPs foi realizada em espectroscopia UV-Vis e ICP-MS. A atividade antimicrobiana foi avaliada por difusão em ágar por poço e microdiluição em caldo. O pH e a concentração de AgNO3 tiveram efeitos significativos na síntese de AgNPs nas condições experimentais. As AgNPs sintetizadas em pH 9,0 e concentração de AgNO3 de 1,5 mM apresentaram maior eficácia contra Staphylococcus aureus (3,17 µg/mL), Escherichia coli (6,35 µg/mL) e Candida albicans (0,79 µg/mL). Os dados mostraram que a síntese de AgNPs por A. flavo-furcatis é influenciada pelo pH e pela concentração de AgNO3, indicando que as AgNPs sintetizadas possuem atividade antimicrobiana contra S. aureus, E. coli e C. albicans.
Prevalence and correlates of depression, anxiety and stress among undergraduate pharmacy students in Nigeria
Authors: Aluh Deborah Oyine , Abba Abubakar , Afosi Afeez Babatunde
Published: September 2020

Background: Mental health disorders are increasingly becoming a global concern among university students. The prevalence of depression, anxiety and stress among pharmacy students in Nigeria is unknown. Objective: This study sought to examine the occurrence of depression, anxiety and stress and associated sociodemographic factors among undergraduate pharmacy students in Nigeria. Methods: The study was an online-based cross-sectional descriptive survey conducted among students from seven pharmacy schools in Nigeria. Students were recruited via their class WhatsApp groups and a link to a Google Form was provided for those who agreed to participate in the study. Data were analysed using IBM Statistical Product and Services Solution for Windows version 21.0. Results: A total of 408 students out of approximately 3,068 students responded to the survey (response rate: 13.32%). The prevalence of depression, anxiety and stress was 44.6%, 63.5%, and 35%, respectively. Depression was found to be strongly correlated with stress (r=0.739, p<0.001) and anxiety (r=0.715, p<0.001). Depression, anxiety and stress scores significantly correlated with perceived academic performance and year of study. There was no significant association between gender, cigarette smoking, type of accommodation, and the levels of depression, anxiety, and stress. Conclusion: The prevalence of depression, anxiety and stress among pharmacy students responding to a survey in Nigeria was high. Students in lower years of study and those with perceived poor academic performance had higher levels of depression, anxiety and stress. More studies are needed to explore the causes of depression, anxiety and stress among pharmacy students.
Letter from the Editors: Special Issue on the 2019 Peter J. Buckley and Mark Casson AIB Dissertation Award
Authors: Mezias John , Newburry William
Published: September 2020

This editorial article introduces the AIB Insights special issue dedicated to the 2019 Peter J. Buckley and Mark Casson AIB Dissertation Award. The issue includes “Essays on Organization, Creativity, and Globalization” by Sungyong Chang; “Foreign Direct Investment in Global Cities and Co-ethnic Clusters: Characteristics, Performance, and Survival” by Dwarka Chakravarty; “Subnational, Regional, Digital: Contemporary Perspectives on the Internationalization of Firms” by Maximilian Stallkamp; and “Bloody Business: Multinational Investment in an Increasing Conflict-Afflicted World” by Caroline Witte.
Essays on Organization, Creativity, and Globalization
Authors: Chang Sungyong
Published: September 2020

This dissertation investigates the impact of globalization of the digital platforms on the discovery of new talent (i.e., new artists) in the music industry. The emergence of digital platforms challenges the received strategy and internationalization theories. Due to its multi-sided nature, digital platforms’ internationalization process depends critically on local complementors in the host countries. This dissertation focuses on (1) when music firms may face difficulties in discovering new talent and (2) whether digital technologies or global media companies help them overcome such difficulties. To identify a causal impact, I utilize the staggered entries of iTunes and Youtube into 29 countries.
Bloody Business: Multinational Investment in an Increasingly Conflict-Afflicted World
Authors: Witte Caroline Theresia
Published: September 2020

This article summarizes the main findings of my PhD dissertation that analyzes the relationships between FDI, political violence and prosperity. Overall, MNEs tend to avoid countries that are afflicted by armed conflict, a type of political violence that poses a relatively continuous type of risk and can have a large negative impact on a firm’s profits. However, a considerable number of MNEs is attracted to conflict countries. I find that armed conflict positively affects greenfield foreign direct investment (FDI) by the most diversified firms, suggesting that entry into conflict countries might allow firms to obtain a first-mover advantage if MNEs.
Trade Policy in the Asia Pacific after Trans-Pacific Partnership
Authors: Weisel Barbara
Published: September 2020

Asia-Pacific countries are building regional economic frameworks and rules designed to promote their economic growth and competitiveness, including the Comprehensive and Progressive Trans-Pacific Partnership, the Regional Comprehensive Economic Partnership, the Pacific Alliance, EU bilateral trade agreements, and China’s Belt and Road Initiative. Under President Trump, the United States abandoned TPP in favor of a bilateral approach, with little to show for it. The nonparticipation of the United States in emerging regional trade architecture and the leadership vacuum it has left will have significant commercial and geopolitical implications, not only for the U.S., but for its partners across the Asia-Pacific region.
Country Familiarity: Three Essays on Entrepreneur Foreign Market Selection
Authors: Clark Daniel
Published: September 2020

Entrepreneurs employ their country familiarity as a cognitive heuristic to help them cope with the cognitively demanding task of selecting an internationalization destination. Country familiarity consists of an individual’s familiarity with a country’s institutions, markets, industry, culture, and products. Across three studies I find a general preference for familiar countries; however, in certain cases high familiarity can produce spontaneous recollections that lower this preference (inverted-U curvilinear). The influence of country familiarity is moderated by international experience, entrepreneurial self-efficacy, individual international entrepreneurial orientation, and the decision-maker’s cognitive style. My research furthers understanding of how entrepreneur internationalization decision-making.
What Drives the Tax Avoidance Strategies Adopted by US MNEs? Understanding the Heterogeneity of Approaches to Corporate Tax Planning in US Multinational Enterprises
Authors: Cooper Maggie
Published: September 2020

This dissertation uses internalization theory to analyse the differences between MNEs approaches to their tax planning strategies. Little is known about the reasons for the differences in strategy between MNEs. Mixed methods of qualitative and quantitative research are used here to examine the MNE’s tax planning in a holistic and systematic manner. This includes in-depth and detailed analysis from the parent-firm level to the subsidiary-level. The study shows the importance of the people within the business in terms of setting the tone for tax planning and strategy and the risk that the organisation is prepared to take.
Should Your IB Research Deal with Power?
Authors: Child John
Published: September 2020

This article is part of the AIB Insights interactive lead article series. The question raised in this article is: Should your IB research deal with power? Although much work has been published on the political relations between MNEs and external institutions, it is noted that “the dynamic processes through which MNEs take political initiatives remain obscure.” The article discusses possible reasons for this lack of knowledge in the literature, sketches out interesting angles IB researchers can take to explore the topic, and presents some tools for analyzing power in MNEs.
OFDI and IFDI Policies Adopted by Central and Eastern European Countries after the Great Recession of 2007-2010
Authors: Götz Marta
Published: September 2020

The significant decline in FDI after the Great Recession, and the accompanying ideological shifts in the role of the state in an economy have called into question the likely changes to be expected in internationalization policies of Central and Eastern Europe (CEE). An interesting observation from this research is that CEE countries commonly associated with an IFDI welcoming culture and neglectful internationalization policies seem to pursue some opposite policies. They have become less friendly towards IFDI but adopted a more positive approach towards the OFDI. Our research identified one Open, seven Competitive, two Capital-based, and three Closed models.
Language Structure and Its Effects on Innovation
Authors: Berman Alexander , Mudambi Ram , Shoham Amir
Published: September 2020

In this study, we evaluate the association between linguistic structures and innovation. We analyze correlations among three linguistic structures – gender distinctions, emphasis on individualism, and hierarchy differentiation – and the aggregate country patenting activity for five years from 2008 to 2012. Our findings indicate that there is a systematic association between language structures and innovation. These insights have significant relevance to the international business field, especially to multinationals’ innovation-related global strategy. The results are also important for policymakers affecting regional and national economic development.
Three Essays on the Influence of Political Connections on Firm International Expansion Strategy
Authors: Albino-Pimentel João
Published: September 2020

This article provides a summary of the three essays in my doctoral dissertation. It aims to show how each essay contributes to better understand how different types of political connections affect firms’ international expansion strategies and performance. The first essay examines how political connections moderate the relationship between host country attributes and international strategy. The second essay investigates how different types of political connections affect firm’s international investments size and riskiness. The third essay analyzes how political connections influence firms’ performance in project finance-based investments.
How to Regain Legitimacy and Relevance in a New Era for international Business: If Not Us, Who?
Authors: Boddewyn Jean J. , Rottig Daniel
Published: September 2020

This article raises the key question of how our field of international business can regain legitimacy and relevance in a new era, and specifically asks: if not us, who? In order to answer this question, we discuss new international business realities and challenges and raise a number of additional questions that we hope will encourage a fruitful dialogue in our field. We further propose specific, actionable projects that we believe the international business community can implement in order to regain legitimacy and relevance.
Global Value Chains, Emerging Markets, and IB Education
Authors: Grosse Robert
Published: September 2020

This article addresses the key challenge for IB teachers: the declining demand for stand-alone IB courses and programs due to the commonly made, fallacious assumption that integrating “international” in other courses by simply adding an “internationally-oriented” chapter to textbooks would suffice. Based on this assumption, the “value added” and uniqueness of IB as its own domain has been questioned. Furthermore, the crucial competences of the IB field are discussed and suggestions for teaching and curriculum changes are added that will facilitate the (re-)establishment of IB as a core discipline, and so contribute to regaining relevance and legitimacy.
Global Strategy and Emerging Markets
Authors: Cuervo-Cazurra Alvaro , Ganitsky Joseph , Luo Yadong , Mezias John
Published: September 2020

We analyze the impact of the home country on the internationalization of firms from emerging markets. We introduce a framework that links the underdevelopment of emerging markets to firm internationalization via firms’ characteristics and strategies.  Specifically, we argue that an underdeveloped economy undergoing pro-market transformations and the underdeveloped pro-market institutions, the major characteristics of emerging markets, influence the ownership, capability and innovation of firms and these, in turn, drive their internationalization and success in global competition.
Beyond Brexit: An Initial Analysis and Questions for the AIB Community
Authors: Ghemawat Pankaj
Published: September 2020

This article discusses the vote of the United Kingdom of Great Britain and Northern Ireland to leave the European Union, commonly known as Brexit. The article explores the implications of Britain’s vote based on the laws of globalization, and also discusses business applications. It concludes with a set of insightful and thought-provoking questions to the AIB community, which the author hopes will fuel the interactive nature of AIB Insights.
Influences on Transfer Effectiveness: An Exploratory Study of Headquarters Transfer of Capabilities to Subunits in the MNC
Authors: Lindahl Olof
Published: September 2020

The role and limitations of headquarters has rarely been considered in research on headquarters-subsidiary transfer despite a lively stream of research on headquarters ability to manage the multinational corporation in other aspects. This suggests that important influences to transfer effectiveness may have been overlooked. The exploratory study that is introduced in this article investigates what influences headquarters transfer of capabilities to subunits in multinational corporations and identify a number of influences to transfer effectiveness that are new to the literature and, based on these, outlines a number of interesting avenues for future research.
Global Subunit Specialization: An Organizational Perspective
Authors: Rodriguez Carlos Adrian
Published: September 2020

This article presents a report of my three-chapter PhD thesis, which studies organizational design issues in offshoring during the formation and evolution stages. Chapter one examines the impact of the subunit scope (functional and geographical breadth) over the project’s efficiency. Chapter two analyzes the role of experience in shaping a firm’s value chain internationalization. Chapter three explores how changes in the organizational architecture of a fine-slicing project affect capability development. The thesis contributes by guiding managers to see fine-slicing not as a one-time strategic decision, but rather one that is sensitive to architectural variables and learning/behavioral processes.
AIB Initiatives in Emerging Markets
Authors: Grosse Robert
Published: September 2020

This article provides a brief historical sketch about the Academy of International Business’ initiatives in emerging markets, takes account of AIB’s current emerging market outreach efforts, and discusses future AIB-related activities, opportunities and challenges in these markets.
The Elephant That Didn’t Get a Visa to Be in the Room
Authors: Barnard Helena
Published: September 2020

The issue of visas does not get much attention in international business, perhaps because visas mainly affect people from developing countries: Exemptions exist for most citizens of Triad countries. Yet there are extensive, opaque and country-specific regulations governing the movement of people across borders. In this essay, I speak about my personal experience in trying to obtain a visa, and reflect how visas act as a barrier to full participation in the global economy, both economically and in the cross-border sharing of knowledge. I suggest the possible value of a global oversight body to regulate how visas are granted.
Multinational Enterprises and Performance: Three Essays at the Interface between International Business and Strategic Management
Authors: Matysiak Lars
Published: September 2020

Why do some firms fail when offshoring and others do not? In an age where the relocation of business activities abroad is common practice, this is an important — yet largely ignored — question with central implications for both research and practice. This dissertation summary suggests that offshoring initiates a more fundamental reconfiguration process that essentially challenges firms’ capacity to manage the complexities of operating an international organization.
Pro-Internationalization Policy and Outward Foreign Direct Investment
Authors: Torres Miguel Matos
Published: September 2020

What is the mechanism, or mechanisms, by which public support incentives influence the internationalization behavior of domestic firms? In this doctoral research I have been able to identify mechanisms through which policy operates upon firms’ international