bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALISIS KASUS COVID-19 BERBASIS GOOGLE TRENDS DI INDONESIA PADA MASA NEW NORMAL
Authors: Nugroho Yoga Dwi , Sandyawan Ignatius
Published: January 2021

Pandemi COVID-19 yang menginfeksi hampir seluruh negara di dunia menimbulkan dampak yang kompleks pada berbagai sektor baik ekonomi, kesehatan, pendidikan dan kehidupan sosial masyarakat. Untuk itu, penting bagi pemerintah mendapatkan informasi mengenai perhatian dan kebutuhan masyarakat sehingga kepanikan dan kebutuhan masyarakat (preventing illness) dapat diberikan solusi. Penelitian ini menggunakan data real time Google Trends sebagai variabel bebas dan kasus terkonfirmasi positif COVID-19 sebagai variabel terikat yang akan dianalisis menggunakan analisis data panel statis fixed effect method (FEM) dan analisis data panel dinamis (GMM regression estimation) dengan tujuan untuk menganalisis perkembangan kasus COVID-19 pada seluruh provinsi di Indonesia yang dikaitkan dengan (banyaknya) ketertarikan masyarakat terhadap informasi terkait COVID-19 baik metode dan bahan yang digunakan untuk menekan penyebaran COVID-19 seperti masker, desinfektan, hand sanitizer, Alat Pelindung Diri (APD) maupun informasi gejala COVID-19 dan mobilitas masyarakat. Selain itu, penelitian ini juga bertujuan untuk menganalisis efek individu setiap provinsi dan efek waktu yang nantinya akan dibandingkan dan dilihat asosiasinya dengan kasus positif COVID-19 dan hasil pencarian gejala COVID-19. Hasilnya pencarian informasi terkait dengan COVID-19 memiliki pengaruh negatif terhadap perkembangan kasus COVID-19. Terdapat 7 variabel yang digunakan dan 6 variabel mengenai informasi yang dicari terkait COVID-19 yang signifikan menggunakan analisis data panel FEM SUR yaitu, APD, korona, hand sanitizer, gejala corona, desinfektan, masker. Adanya efek dinamis dari variabel dependen maka digunakan regresi data panel dinamis FD-GMM yang menunjukkan data estimasi lebih baik dan terdapat 6 variabel yang signifikan yaitu, APD, korona, hand sanitizer, gejala corona, desinfektan, dan lag variabel dependen.
PENERAPAN MODEL COBB-DOUGLAS DALAM PEMODELAN FUNGSI PRODUKSI DAN EVALUASI KINERJA FAKTOR PRODUKSI PADI DI INDONESIA TAHUN 2016
Authors: Sutikno Lutfi Hamdani
Published: January 2021

Indonesia merupakan negara produsen padi terbesar ketiga di dunia pada tahun 2016, dengan produksi padi sebesar 74.5 juta ton (FAO, 2017). Namun capaian produksi padi Indonesia tersebut belum ditunjang oleh produktivitas yang memadai. Produktivitas padi Indonesia masih relatif rendah yakni sebesar 5,18 ton per hektare, lebih rendah jika dibandingkan Bangladesh dan Vietnam yang memiliki nilai produksi padi lebih sedikit. Ketidakoptimalan produktivitas padi dapat dipengaruhi oleh berbagai hal, salah satunya kinerja faktor produksi yang secara langsung menunjang nilai produksi padi. Faktor produksi tersebut yakni luas lahan sawah (X1), jumlah petani (X2), serta asupan gizi bagi tanaman berupa pupuk organik dan anorganik bersubsidi (X3). Penerapan model Cobb-Douglas dalam pemodelan fungsi produksi padi di Indonesia tahun 2016 diselesaikan dengan transformasi Regresi Linier Berganda (RLB) yang menghasilkan model regresi yang fit dan proper. Terbentuk fungsi produksi padi
PEMODELAN DAN PENERAPAN METODE RFM PADA ESTIMASI NILAI KONSUMEN (CUSTOMER LIFETIME VALUE) MENGGUNAKAN K-MEANS CLUSTERING MACHINE LEARNING
Authors: Laksono Bagaskoro Cahyo , Wulansari Ika Yuni
Published: January 2021

Krisis Covid-19 berdampak pada revenue perusahaan, jika perusahaan tidak meningkatkan strategi pemasaran yang tepat terhadap konsumen, akan beresiko gulung tikar karena tidak memiliki target pasar yang jelas. Disamping itu, perusahaan dapat mengembangkan bisnisnya menggunakan big data untuk mendukung decision making. Big data dalam industry e-commerce yang mencakup ukuran dan kecepatan transaksi yang tinggi dapat digunakan untuk menganalisis perilaku konsumen bahkan memprediksi nilai konsumen. Pada zaman sekarang perusahaan mulai mengembangkan ketertarikan bisnis yang berorientasi konsumen daripada berorientasi produk. Salah satu cara yang dapat digunakan untuk menentukan nilai konsumen yaitu dengan menghitung Customer Lifetime Value (CLV). Dengan mengetahui CLV di level individu, akan berguna untuk membantu pengambil keputusan untuk mengembangkan segmentasi konsumen dan alokasi sumber daya. Penting dilakukan segmentasi atau pengelompokkan konsumen yang menggambarkan kelompok loyalitas konsumen. Oleh karena itu tujuan dalam penelitian ini adalah melakukan penghitungan CLV dan segmentasi konsumen dengan menggunakan metode analisis RFM dengan K-Means Clustering Machine Learning Model. Tahapan analisis diantaranya mendefinisikan RFM Segmentation Value yang merupakan clustering yang dibangun dari angka kumulatif yang berisi penjumlahan Recency, Frequency dan Monetary Level yang dimiliki masing-masing konsumen. Kombinasi nilai level yang tercipta berkisar antara 0,1,2,3,4,5,6 yang artinya semakin tinggi nilainya maka semakin berharga konsumen tersebut. Pada akhirnya, metode segmentasi konsumen yang di bangun penulis dapat digunakan untuk optimasi strategi perusahaan untuk mendapat profit yang maksimum. Metode ini dapat diterapkan pada berbagai kasus dan perusahaan lain. Hasil penelitian ini diharapkan dapat membantu perusahaan untuk bertahan di tengah krisis akibat Covid-19.
ANALISIS FAKTOR TINGKAT PENGANGGURAN TERBUKA DENGAN METODE GEOGRAPHICALLY WEIGHTED LASSO
Authors: Lestari Siti Sarah Sobariah , Meimela Aida , Revildy Windy David
Published: January 2021

Tingkat pengangguran terbuka di Jawa Barat Pada Tahun 2019 mencapai 7,99% menurut Badan Pusat Statistik (BPS) angka ini merupakan angka tertinggi di Indonesia. Permasalahan tingginya tingkat pengangguran tentunya akan berdampak kepada aspek perekonomian yang mengakibatkan tidak maksimalnya tingkat kemakmuran (Amalia, 2019) sehingga, diperlukan penanganan yang tepat untuk mengatasi permasalahan ini. Akan tetapi penelitian yang sudah dilakukan masih mengarah pada hasil yang bersifat global tanpa mempertimbangkan keberagaman karakteristik di setiap daerah. Sebagaimana kita ketahui, bawasanya setiap daerah memiliki karakteristik yang berbeda sehingga analisis berdasarakn pada pemodelan regresi global kurang tepat. Adanya efek spasial pada Tingkat Pengangguran terbuka mengakibatkan kemungkinan terjadinya keragaman spasial. Analisis GWR yang merupakan perluasan dari regresi global mampu mengakomodir permasalahan tersebut. Namun, analisis ini masih memiliki kelemahan salah satunya apabila terjadi multikoliniritas, pemodelan yang dilakukan dengan GWR kurang optimal.Geographically Weighted Lasso (GWL) merupakn teknik yang menggunakan pendekatan Lasso dalam model GWR untuk mengatasi masalah multikolinieritas disamping itu, model GWL juga dapat sekaligus menyeleksi variabel yang tidak signifikan dengan cara menyusutkan nilai koefisien regresi sampai ke nol. Sehingga variabel-variabel dengan koefisien regesi nol tidak berpengaruh signifikan (Wheeler D 2009). Dalam penelitian ini diperoleh bahwa signifikansi variabel yang mempengaruhi tingkat pengangguran terbuka disetiap daerah berbeda-beda dimana variabel Angkatan kerja yang tidak berijazah, Angka Putus Sekolah, Lowongan Kerja, dan Kepadatan Penduduk memberikan pengaruh yang signifikan pada sebagian besar kota dan kabupaten di Jawa Barat. Sedangkan kabupaten Bandung hanya dipengaruhi signifikan oleh variabel IPM. Pemodelan dengan menggunakan GWL memberikan koefisien determinansi yang lebih tinggi dibandingkan dengan model regresi global dan GWR.
ANALISIS PERBANDINGAN DESAIN SAMPLING SURVEI KERANGKA SAMPEL AREA (KSA)
Authors: Zikra Hazanul , Buana Widyo Pura
Published: January 2021

Badan Pusat Statistik (BPS) terus melakukan inovasi dalam rangka menghasilkan data pangan yang akurat, termasuk bekerja sama dengan Badan Pengkajian dan Penerapan Teknologi (BPPT) dalam mengembangkan metode survei KSA untuk mengestimasi luas panen padi. Meskipun sudah menerapkan kaidah sampling yang objektif, namun masih perlu dilakukan kajian terutama adanya potensi bias dari estimator survei KSA terutama untuk sawah-sawah dengan karakteristik tidak beraturan, kecil dan menyebar. Salah satu potensi penyebab bias dengan karakteristik sawah tidak beraturan adalah penggunaan segmen berbentuk persegi berukuran 300 meter × 300 meter menimbulkan potensi titik amatan tidak jatuh di sawah. Penelitian ini bertujuan menganalisis perbandingan beberapa alternatif desain sampling KSA, yaitu dot sampling method, two-phase systematic unclustered point sampling, dan irregular segment shape sampling atau kerangka sampel segmen yang mengikuti bentuk sebaran sawah. Metode yang digunakan adalah simulasi sampling dengan opsi desain sampling KSA tersebut dengan berbagai opsi jumlah sampel menggunakan peta populasi sawah di Kecamatan Denpasar Timur pada bulan Februari 2019. Perbandingan hasil simulasi dianalisis dengan pengujian beda rata-rata MSE dan optimasi biaya pada seluruh desain sampling. Kesimpulan dari penelitian ini adalah rancangan sampling menggunakan irregular segment shape dengan 3 (tiga) segmen memberikan tingkat akurasi dan efisien yang lebih baik dibandingkan rancangan sampling dengan kerangka sampel segmen berbentuk persegi.
PANDEMI COVID-19 DALAM PERSPEKTIF DEMOGRAFI
Authors: Styawan Dwi Agus
Published: January 2021

Covid-19 telah menjadi tantangan global yang berdampak pada berbagai sektor kehidupan. Kajian covid-19 dalam perspektif demografi sangat diperlukan sebagai dasar untuk mengetahui kelompok penduduk yang rentan terpapar covid-19. Penelitian ini bertujuan untuk mengkaji karakteristik demografi dan komorbiditas penduduk Indonesia terkonfirmasi positif covid-19. Sumber data penelitian ini adalah data sekunder yang berasal dari Gugus Tugas Percepatan Penanganan Covid-19 Indonesia. Penelitian ini menggunakan metode deskriptif dengan menganalisis grafik sesuai karakteristik demografi dan komorbiditas penduduk terkonfirmasi positif covid-19. Hasil penelitian menunjukkan bahwa laki-laki, berumur produktif, dan memiliki penyakit penyerta seperti hipertensi, diabetes mellitus, dan panyakit jantung merupakan kelompok rentan terpapar covid-19. Adapun penduduk laki-laki, berusia lanjut, dan memiliki penyakit penyerta beresiko lebih tinggi mengalami kematian akibat covid-19. Oleh karena itu, pemerintah hendaknya membatasi mobilitas penduduk terutama penduduk berumur produktif dan menerapkan protokol kesehatan secara ketat agar penularan covid-19 dapat dihentikan. Selain itu, pemerintah juga harus memberikan pelayanan kesehatan maksimal kepada penduduk lanjut usia yang terpapar covid-19 untuk menekan resiko kematian.
EFFICIENCY INVESTIGATION OF THE WAYS OF COMBINING NPP WITH A HYDROGEN COMPLEX FOR THE PURPOSE OF SALE OF HYDROGEN AND GENERATION OF ADDITIONAL ELECTRIC POWER
Authors:   Yuri Gagarin State Technical University of Saratov, Yurin V.E. , Egorov A.N. ,   Saratov Scientific Center of the Russian Academy of Sciences, Bashlykov D.O. ,   Rusatom Automated Control Systems JSC, Moskalenko A.B. ,   Yuri Gagarin State Technical University of Saratov
Published: January 2021

With an increase in the share of NPPs in the energy system, it becomes necessary for them to participate in the regulation of the electric load schedule. At the same time, the operation of the NPP with the maximum utilization factor of the installed capacity of the reactor was economically and technically justified. One of the promising ways to solve this problem is to install consumers-regulators at NPPs. The hydrogen energy complex can be effectively used as a consumer-regulator. The authors have previously developed an autonomous hydrogen energy generating complex, scientifically substantiated its economic efficiency. As the study has shown, the economic efficiency of an autonomous hydrogen energy complex directly depends on the sale tariffs for electricity. The low cost of electricity sold leads to a deterioration in economic indicators, up to a lack of recoupment. In this regard, as an alternative option, this work considers the possibility of selling hydrogen and oxygen as a commercial product at existing prices. A comparative study for a range of electricity tariffs and prices for hydrogen and oxygen was carried out on the basis of the methodology presented earlier by the authors, which makes it possible to study ways to improve NPPs on the basis of a comprehensive analysis of economic efficiency, safety and system effects achieved during the installation of new and modernization of existed equipment. The results obtained make it possible to choose the type of hydrogen energy complex depending on the operating conditions for the selected region of operation.
Advanced Electrode Materials in Lithium Batteries: Retrospect and Prospect
Authors: Shen Xin , Zhang Xue-Qiang , Ding Fei , Huang Jia-Qi , Xu Rui , Chen Xiang , Yan Chong , Su Fang-Yuan , Chen Cheng-Meng , Liu Xingjiang , Zhang Qiang
Published: January 2021

Lithium- (Li-) ion batteries have revolutionized our daily life towards wireless and clean style, and the demand for batteries with higher energy density and better safety is highly required. The next-generation batteries with innovatory chemistry, material, and engineering breakthroughs are in strong pursuit currently. Herein, the key historical developments of practical electrode materials in Li-ion batteries are summarized as the cornerstone for the innovation of next-generation batteries. In addition, the emerging electrode materials for next-generation batteries are discussed as the revolving challenges and potential strategies. Finally, the future scenario of high-energy-density rechargeable batteries is presented. The combination of theory and experiment under multiscale is highlighted to promote the development of emerging electrode materials.
PENGARUH AVERAGE TAX RATE, SIZE,GROWTH, FIXED ASSET RATIO, FINANCIAL LEVERAGE, DAN WORKING CAPITALTERHADAP PROFITABILITY
Authors: JIMENA ARILYN ERIKA , BENY BENY , FRANSISCA FRANSISCA
Published: January 2021

The purpose of this research is to analyze empirically the influence of average tax rate, size, growth, fixed asset ratio, financial leverage, and working capital toward profitability. The object of this research is food and beverage companies that listed in Indonesia Stock Exchange period 2004-2014. The purposive sampling is used as sampling technique, in which only 6 companies meet the sampling criteria, resulting 66 data obsevations used in this research. Data were analyzed using Eviews8 panel data regression with fixed effect model to test the hyphotesis. The results shows that financial leverage and working capital have influence to profitability. In the other hand, average tax rate, size, growth, and fixed asset ratio have no influence to profitability. Overall, the independent variables influence financial leverage simultaneously.
THE INFLUENCE OF STORE ENVIRONMENT, SALES PROMOTION AND PERCEIVED VALUE ON PURCHASE DECISION
Authors: CHAPHIRAY CHAPHIRAY , INDRIYANTI IRMA SATYA
Published: January 2021

The purpose of this research is to test and analyze influence of Store Environment, Sales Promotion, and Perceived Value to Purchase Decision to Customer Ramayana in East Jakarta. The research design used in descriptive research and causality research. The sampling in the study used 206 respondent with purposivesampling. The research data is processed with IBM Statistic 22.0 as a tool. This study uses multiple regression analysis. The result showed that Store Environment, Perceived Value influence Purchase Decision, but for Sales Promotion not influence to Purchase Decision. Overall, independent variables affect Loyalty simultaneously.
Neuroretinitis secondary to dual infection of Toxoplasma gondii and Bartonella hensalae
Authors: Siti-Khadijah Abdul Rahman , Yaakub Azhany , Muhammed Julieana , Wan Hitam Wan-Hazabbah
Published: January 2021

A 73-year-old lady with underlying diabetes presented with acute loss of central vision in the left eye. Examination revealed visual acuity of 6/60 in the left eye with positive relative afferent pupillary defect and optic disc swelling with macular oedema. Right eye visual acuity was 6/12 with unremarkable findings. Optical coherence tomography (OCT) showed elevated macular with ceacocentral field defect on Humphrey visual field. Connective tissue screening and tubercular screening were negative. Serological screening for Toxoplasma sp and Bartonella sp were positive. She was diagnosed as neuroretinitis secondary to both infections and started on oral azithromycin 500 mg once a day and oral corticosteroid. Her final vision improved to 6/12 with normal optic disc and resolved macular oedema.
Sweet disaster: use of honey-based eye drops as an alternative treatment for vernal keratoconjunctivitis
Authors: Kheng Leong Kenneth Teow , Jennifer Mary Louis Rebecca , Yin Peng Lai , Alias Rohanah , Mohd Khialdin Safinaz
Published: January 2021

A 16-year-old boy with underlying bronchial asthma, vernal keratoconjunctivitis, and bilateral eye steroid-induced glaucoma presented with right eye itchiness, redness, and progressive painful blurring of vision for the past 3 weeks. His mother had been treating him with honey-based eye drops purchased from an unregistered source/traditional healer. On presentation his right visual acuity was counting fingers, the cornea was hazy, and a small central stromal abscess with a large endothelial plaque was seen in the anterior chamber. He was treated for right eye fungal keratitis and subsequently admitted for intensive treatment. He showed marked improvement and was discharged. His final vision on follow-up was 6/15.
A surgical cause of pseudopapilledema
Authors: Shee Wen Chua , Shee Kiang Teo , Ami Malisa , Mustapha Mushawiahti , Seng Fai Tang
Published: January 2021

We report a case of vitreopapillary traction mimicking optic disc swelling in a 73-year-old female with pseudophakia in the left eye and satisfactory postoperative vision of 6/6 and N5 two years prior. She presented with insidious onset of blurred vision in her left eye for two months. She was referred to Universiti Kebangsaan Malaysia Medical Centre (UKMMC) for further investigations of apparent optic disc swelling in the left eye by a general ophthalmologist. Her left eye vision was 6/18, pinhole 6/12, with near vision at N6. There was no relative afferent pupillary defect and anterior segment examination was normal. Examination of the posterior segment revealed a pink optic disc with blurred and elevated margins without hyperaemia. Vessels of the optic nerve head appeared normal and a lamellar macular hole was present with dull foveal reflex clinically. Right eye examination was normal. Optical coherence tomography (OCT) of the left eye using the raster line scan showed vitreopapillary traction surrounding the optic disc and vitreomacular traction (VMT) with lamellar macular hole. The patient was counselled for surgical release of VMT, however, she opted for conservative management.

Peripapillary vitreoretinal traction is a rare cause of pseudo-optic disc swelling. Thorough fundus examination with the help of OCT is crucial in making a prompt diagnosis, preventing unnecessary investigations, and evaluating other retinal pathologies which may benefit from treatment.
Infectious keratitis: findings from a retrospective review in the central zone of Sarawak
Authors: Jiah Bou Koay , Siew Tan Teng , Wei Chua Ter , Mun Tan Li
Published: January 2021

Introduction: Infectious keratitis is caused by inflammation of the cornea from an infectious pathogen that usually results in corneal scarring. It is a major cause of visual impairment globally. The management of infectious keratitis is challenging, and unfortunately, there is no proper study on this issue in the central zone of Sarawak to date.

Purpose: To identify the demographic characteristics, risk factors, and etiological agents of patients with infectious keratitis in Sibu Hospital, Sarawak, Malaysia.

Design of the study: Retrospective study.

Materials and methods: Data were collected and reviewed from medical records of all patients with infectious keratitis in Sibu Hospital from January 2013 up to May 2018.

Results: A total of 139 patients (143 eyes/cases) were included in the study. The average age of affected individuals was 47.39 years. The most frequently affected patients fell within the age group of 21-30 years (18.9%). The male-to-female ratio was 1.65:1, with 61.5% of patients being males and 38.5% being females. Seventy-four cases were noted to have predisposing factors before the manifestation of symptoms. The commonest predisposing factors were ocular trauma (55.4%), followed by contact lens wear (29.7%), recent ocular surgery (13.5%), and a recent history of swimming (7.4%). At least one pathogen was isolated in 63.1% of the 38 cases that were tested for corneal scraping culture and sensitivity. Pseudomonas aeruginosa was identified as the most common causative pathogen in our study.

Conclusion: Ocular injury stood out as the most common risk factor for infectious keratitis in this study and Pseudomonas aeruginosa was the most common etiological pathogen. A good grasp of local epidemiology and microbial profile of infectious keratitis is essential in aiding and guiding the management of infectious keratitis in hopes of better outcomes for all affected patients.
Leukostatic retinopathy: a sight-threatening complication of chronic myeloid leukaemia with severe hyperleukocytosis
Authors: Lim Chuan Chun , Mohd Ramli Norlina
Published: January 2021

Retinopathy secondary to chronic myeloid leukemia (CML) commonly manifests as venous dilation and tortuosity, retinal hemorrhages, microaneurysms, and cotton-wool spots which are similar to features of non-proliferative diabetic retinopathy or hypertensive retinopathy. However, massive vitreous hemorrhage is rarely encountered, especially among those treated with chemotherapy. We report a case of a young CML patient in accelerated phase, presenting with bilateral painless sudden visual loss. Fundus examination showed bilateral dense vitreous hemorrhage. Laboratory results showed thrombocytopenia with a very low platelet count. Magnetic resonance imaging (MRI) of the brain and orbit showed subacute intraparenchymal hemorrhages and bilateral intraocular hemorrhages. We performed pars plana vitrectomy (PPV) and endolaser on the left eye, which had more extensive vitreous hemorrhage. At one-week follow-up, the patient unfortunately developed a retinal detachment. The patient underwent a second PPV with endolaser and insertion of silicone oil. Despite the prompt surgical intervention, the patient developed an ischemic retina resulting in poor visual prognosis. One month later, we performed PPV and endolaser on the right eye. Postoperatively, her vision improved significantly from hand movement to pinhole vision 6/45. Dense vitreous hemorrhage is a rare complication of childhood leukemia. General physicians should refer leukemic patients for ophthalmic evaluation. Awareness of potentially blinding complications of CML and prompt referral upon diagnosis is warranted for early detection and treatment. Reduced awareness of this potentially blinding complication may result in poor visual outcome.
Preoperative keratometry agreement: vector comparison between the IOLMaster 500, Galilei G2, and a Takagi autorefractor
Authors: Wallace Henry , Li Sunny Sixiao , McKelvie James , Misra Stuti
Published: January 2021

Introduction: Preoperative cataract assessment may involve multiple biometric instruments and it is important that clinicians are aware of the accuracy, limitations, and interchangeability of keratometry measurements conducted on these instruments.

Purpose: The purpose of the current study was to determine the agreement of keratometry magnitude and axis measurements obtained using three commonly used clinical keratometers.

Design of the study: Prospective, comparative study.

Materials and methods: One-hundred eyes of 100 prospectively enrolled patients listed for cataract phacoemulsification were recruited. Preoperative keratometry magnitude and axis measurements were obtained using the Galilei-G2 Dual Scheimpflug Analyzer (Ziemer Ophthalmic Systems AG, Port, Switzerland), IOLMaster 500, and Takagi ARKM-200 autokeratometer (Takagi Seiko Co., Ltd, Nagano-ken, Japan). Inter-device agreement in corneal spherical equivalent, corneal cylinder vectors, and corneal cylinder magnitude was assessed using the Bland-Altman method.

Results: One participant was excluded because of incomplete data. The Galilei-G2 reported the lowest mean keratometry (43.96 ± 1.71 D) and the IOLMaster reported the highest (43.99 ± 1.65 D). A single statistically significant difference occurred in the corneal cylinder vector analysis between the IOLMaster 500 and the three-instrument pooled mean (mean difference = -0.238 D, P = 0.04). No other statistically significant differences were observed for any instrument for any measured parameter. Excluding the vector difference analysis (range = -0.175 – -0.238 D), mean differences between individual instruments and the three-instrument pooled mean did not exceed 0.025 D (P > 0.05).

Conclusion: The Galilei-G2, IOLMaster 500 (Carl Zeiss Meditec AG, Oberkochen, Germany), and Takagi ARKM-200 autokeratometer produce accurate keratometry and axis measurements that are comparable between instruments. The instruments could be used interchangeably in clinical practice in scenarios where accurate examinations cannot be obtained using one of the instruments.
Rhegmatogenous retinal detachment and full-thickness macular hole induced by lightning
Authors: Haw Qian Zhi , Vendargon Francesca Martina , Ling Kiet Phang
Published: January 2021

A 31-year-old gentleman was remotely struck by lightning and complained of blurred vision in his left eye. He was diagnosed with left eye anterior uveitis and full-thickness macular hole (FTMH), and subsequently referred for vitreoretinal intervention. On examination, his left-eye vision was hand movement. Anterior uveitis had resolved with no cells in the anterior chamber. Posterior subcapsular cataract 2+ was noted. There was a FTMH and partial posterior vitreous detachment (PVD) confirmed by optical coherence tomography (OCT). Right eye was normal with 6/6 vision. At one- month follow-up, the macular hole was closed spontaneously but localised rhegmatogenous retinal detachment (RRD) was noted in the inferior retina with macula-on. There were multiple holes in the inferior equatorial region surrounded by hyper- and hypopigmented retinal atrophy. The patient underwent phacoemulsification, intraocular lens implantation, vitrectomy, and gas tamponade (C3F8 14%). At one week postoperative, he had recurrent retinal detachment with multiple new atrophic holes noted. He underwent a second vitrectomy with silicone oil tamponade. Best-corrected visual acuity (BCVA) in his left eye two months after surgery was 6/45 and the retina had reattached.
Cases of cytomegalovirus retinitis in patients treated for cancer
Authors: Ahmad Marium Jamaluddin , Kamalden Tengku Ain , Khaliddin Nurliza , Iqbal Tajunisah
Published: January 2021

Cytomegalovirus (CMV) retinitis is an opportunistic infection affecting immunocompromised patients. This case series describes 2 patients aged 19 and 10 years who were undergoing cancer treatment and were referred for complaints of worsening blurred vision. The retinal findings in the first patient showed multiple yellowishsubretinal areas with haemorrhages, while in the second patient there was presence of frosted branch angiitis. Confirmation of diagnosis was done using PCR of vitreous samples and blood CMV levels. Both tested negative for HIV. Both received intravitreal and systemic ganciclovir. It is important for ophthalmologists to consider CMVretinitis in all patients with any form of immunosuppression.
Small-gauge vitrectomy for advanced diabetic eye disease: outcomes and predictive factors for poor postoperative vision
Authors: Mustapha Mushawiahti , Yoong Tan Chim , Gobal Tevanthiran A/L , Chong Win Inn , Tengku Zulkeplee Tengku Nadhirah , Raja Iskandar Raja Yunalis , Md Basri Siti Mahirah , Zulkafli Muhammad Amirul Faris , Md Din Norshamsiah , Naffi Ainal Adlin , Chin Terence , Chandrasegaran Paranthaman Thevar , Hod Rozita , Bastion Mae-Lynn Catherine
Published: January 2021

Objective: To evaluate the anatomical and visual outcomes of small-gauge vitrectomy in patients with advance diabetic eye diseases (ADED) and the predictive factors for poor visual outcome.

Materials and methods: A retrospective study was conducted from 2009 to 2014. Data at baseline, 6 months, and 12 months post-surgery were collected along with baseline demographic data, indications of surgery, systemic associations, visual and anatomical outcome, and postoperative complications. Poor visual outcomewas defined as visual acuity worse than 6/36.

Results: A total of 158 eyes from 133 patients were recruited. Mean age was 54.01 ± 11.57 years and mean follow-up was 9.9 ± 3.7 months. Indications for vitrectomy were vitreous haemorrhage (VH, 77 eyes [48.7%]), tractional retinal detachment (TRD) with macular involvement (75 eyes [47.5%]), and other causes in 6 eyes (3.8%). There was visual improvement in 59.3% of patients, 23.6% worsened, and 17.1% stabilized at 12 months post-surgery. Patients with VH (75.4%) showed significant improvement compared to patients with TRD (48.3%). Successful anatomical outcomes were achieved in VH (98.2%) and TRD (96.7%). However, patients with TRD were found to have a 2.4-fold higher risk of having poor visual outcomes.

Conclusion: Small-gauge vitrectomy for ADED resulted in excellent visual and anatomical outcomes. Eyes with TRD were at a higher risk of developing poor visual outcomes.
Retinal nerve fibre layer thickness measured by spectral domain optical coherence tomography amongst early primary open-angle glaucoma patients at Hospital Melaka
Authors: Silim Anhar Hafiz , Raja Omar Raja Norliza , Othman Othmaliza , Nasaruddin Rona Asnida , Din Norshamsiah Md
Published: January 2021

Introduction: Glaucoma is second only to cataract as a cause of blindness worldwide and Asians account for almost half the cases. Retinal nerve fibre layer (RNFL) assessment is an important objective method for diagnosis and monitoring of glaucoma as it develops earlier than the development of visual field defects.

Purpose: To estimate the proportion of primary open-angle glaucoma (POAG) patients with normal RNFL thickness (RNFLT) amongst early POAG patients who were under follow-up at the Ophthalmology Department, Hospital Melaka (Melaka, Malaysia).

Study design: Observational cross-sectional study.

Materials and methods: Consecutive sampling of 64 POAG patients who were diagnosed as early POAG as defined by the Glaucoma Staging System 2 (GSS 2) into stage 1 and 2 on Octopus visual field test were recruited in this study. Data collected included demographic data, refraction, slit-lamp examination, intraocular pressure (IOP), gonioscopy, peripapillary retinal nerve fibre layer thickness (RNFLT) measured by spectral-domain optical coherence tomography (SD-OCT), and fundus photography.

Results: Among 64 eyes, 57.8% were found to have normal and 42.2% to have abnormal RNFLT classification. There was no difference in terms of age, gender or ethnicity between those with normal and abnormal RNFLT. Mean IOP at presentation, mean duration of POAG, and mean spherical dioptres were compared between the two groups. Only mean spherical dioptres showed a significant difference between the two groups, p < 0.001. An increase of spherical dioptres also had a moderate positive correlation with RNFLT in most optic disc quadrants except the nasal, temporal, superonasal, and inferonasal quadrants.

Conclusion: OCT cannot be used as a diagnostic tool alone, especially in early glaucoma, as it showed a normal RNFLT in almost half the patients. RNFLT in early POAG had significant correlation with spherical dioptres in most quadrants.
Treatment of conjunctival squamous cell carcinoma: balancing disease eradication with minimising treatment-induced morbidity
Authors: McLintock Cameron , McKelvie James , Hamada Samer
Published: January 2021

A 41-year-old male presented with a large non-pigmented lesion on the ocular surface involving 8 clock hours of limbus, bulbar conjunctiva, and palpebral conjunctiva. Incisional biopsy confirmed poorly differentiated conjunctival squamous cell carcinoma (SCC). It was staged as a T3, N0, M0 lesion. Treatment was with surgical excision, amniotic membrane transplant, and buccal mucosa graft. Three weekly cycles of 0.04% mitomycin C were administered postoperatively. Six months following excision, although there was no evidence of residual conjunctival SCC, the patient suffered from poor vision, significant pain, and diplopia due to severe dry eye, limbal stem cell deficiency, and symblepharon.This case illustrates the difficult clinical decisions which confront the clinician when treating conjunctival SCC, particularly with balancing the need to eradicate the disease to prevent local invasion and metastatic spread on the one hand and minimising ocular morbidity on the other.
Spontaneous retinal pigment epithelial rip
Authors: Arumugam Kosyilya , Mohd Zain Ayesha , Mustapha Mushawiahti
Published: January 2021

This is a case report of a spontaneous retinal pigment epithelial (RPE) rip in a 64-year-old woman who presented with progressive, painless, blurring of vision in her right eye for 2 weeks. Her vision was 6/60 in the right eye and 6/6 in the left eye. On fundoscopy, there was a large depigmented area over the right posterior pole. A large area of RPE rip involving the fovea was revealed via optical coherence tomography and angiogram. Spontaneous RPE rip is a rare manifestation. However, when the fovea is involved the visual prognosis is poor. This article aims to highlight the vital role of multimodal imaging in aiding the diagnosis of RPE rips or tears.
Corneal foreign body self-removal using polymer banknotes
Authors: Ch’ng Tun Wang , Koh Koon Ling , Teh Niven Chong Seong , Chong Mei Fong
Published: January 2021

Since the introduction of polymer banknotes, they have become a new tool for corneal foreign body (CFB) self-removal. Being easily available, lightweight, and sturdy, polymer papers have become a popular and innovative method to dislodge CFB. Although ophthalmology services are easily accessible in Malaysia, ignorance, lack of health awareness, and the desire to avoid medical costs are among the reasons why patients remove CFB themselves. The sequalae span from only a faint scar with relatively good vision to total blindness. Our case series highlights three cases of CFB self-removal using polymer banknotes and their sequalae. To echo what has been known previously, self-awareness and occupational hazard education remain the most important and effective way to prevent vision loss.
Leber’s hereditary optic neuropathy
Authors: Low Adeline , Neoh Yee Ling , Foo Siu Wan , Kadir Azida J.
Published: January 2021

Leber’s hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disease caused by several point mutations in mitochondrial DNA. We present the case of a healthy 12-year-old Chinese boy who presented with bilateral, painless, subacute loss of central vision (more severe in the left eye the than right eye) for 1 week. No abnormalities were detected on magnetic resonance imaging of the brain and orbit. Serial Humphrey visual field tests initially showed a centrocaecal scotoma that worsened progressively. Cerebrospinal fluid samples and blood investigations showed normal results. A trial of steroid therapy was commenced with not much improvement in the patient’s vision. A blood sample was then sent for LHON genetic testing and a mitochondrial DNA (mtDNA) G11778A pathogenic mutation was detected. The same mutation was also present in the patient’s mother.
CARACTERÍSTICAS DESEABLES DE PLANTAS DE PEPINO CRECIDAS EN INVERNADERO E HIDROPONÍA EN ALTAS DENSIDADES DE POBLACIÓN
Authors: Ortiz-Cereceres Joaquín , Sánchez-del Castillo Felipe , Mendoza-Castillo Ma. del Carmen , Torres-García Araceli
Published: January 2021

La contribución de algunos caracteres morfológicos de la planta de pepino (Cucumis sativus L.) en el rendimiento por planta y por unidad de superficie, factibles de incorporarse a un arquetipo idóneo para su manejo en un sistema de producción basado en despuntes tempranos de la yema terminal (plantas de 1 m de altura) y alta densidad de población, se evaluó en ambientes poco restrictivos (invernadero e hidroponía). Se establecieron dos experimentos; en el Experimento I se evaluaron 11 variedades en dos densidades de población (9 y 16 plantas m-2); en el Experimento II se evaluaron cuatro variedades que representaron dos grupos de características contrastantes. En ambos experimentos se utilizó un diseño experimental de bloques al azar y un arreglo de tratamientos en parcelas divididas; la densidad de siembra correspondió a la parcela grande y las variedades a la parcela chica. Las variedades ‘Monarch’ y ’Sprint 440’ mostraron el mayor número de características deseables para conformar un arquetipo de pepino adecuado al sistema, como: tallo grueso (7 y 6.7 mm), más área foliar (43.5 y 39.7 dm2) y más número de frutos por planta (7.4 y 7.3), en contraste con las variedades ‘Moctezuma’ e ‘Indy’. Las variedades con mayor área foliar produjeron dos frutos más por planta que las de menor área, carácter que fue el que tuvo mayor relación directa con el rendimiento. No hubo diferencias en rendimiento por unidad de superficie al aumentar la densidad de 9 a 16 plantas m-2, por lo que se recomienda usar la más baja para este sistema de producción.
PATRÓN VARIETAL Y RENDIMIENTO DE GRANO DE MAÍCES LOCALES DEL VALLE DE TEHUACÁN, PUEBLA
Authors: A. López Pedro , Ortiz-Torres Enrique , Gil-Muñoz Abel , Guerrero-Rodríguez Juan de Dios , Taboada-Gaytán Oswaldo R. , López-Sánchez Higinio , Hernández-Guzmán J. Arahón
Published: January 2021

El Valle de Tehuacán, en el estado de Puebla, México, es reconocido como centro de domesticación y diversidad de varias especies cultivadas, entre ellas el maíz (Zea mays L.); sin embargo, sólo un trabajo ha reportado el potencial elotero de las poblaciones locales de maíz de esa región y no hay estudios sobre el patrón varietal y su rendimiento de grano. El objetivo de este estudio fue identificar el patrón varietal de poblaciones locales del Valle de Tehuacán, para seleccionar las sobresalientes en rendimiento de grano y formar la base genética para un proceso de mejoramiento genético local. En el ciclo PV 2009 se ensayaron, bajo riego, 95 poblaciones locales de maíz, tres testigos raciales y dos testigos comerciales (híbridos), mediante el diseño látice simple 10 × 10, en tres localidades con suelos que presentan valores altos de pH y bajos niveles nutrimentales. Las variables registradas fueron rendimiento de grano, variables fenológicas, agronómicas y características de grano, mazorca y olote, a las cuales se les aplicó un análisis estadístico combinado. Las poblaciones locales de maíz mostraron mejor adaptación que los testigos. El patrón varietal del Valle de Tehuacán estuvo conformado con maíces de grano blanco (60 %), azul (35.8 %) y rojo (4.2 %). El 95 % de las poblaciones locales fueron precoces, con 82 a 96 días a floración femenina (DFF), un testigo comercial se ubicó en el estrato ultraprecoz (menos de 82 DFF) y otro en el precoz. Los maíces precoces rindieron más que los ultraprecoces y existieron diferencias estadísticas entre poblaciones en 85 % de las variables. Las poblaciones locales superaron ampliamente en rendimiento de grano a los testigos comerciales. En éstas, mediante la aplicación de dos modelos, se seleccionaron las 10 mejores con base en su rendimiento promedio y menor interacción con el ambiente. El patrón varietal de las poblaciones locales de maíz del Valle de Tehuacán está integrado por poblaciones precoces de grano blanco, azul y rojo, en las que se definió su base genética para un proceso de mejoramiento genético local.
PRUEBAS DE UNA SEMBRADORA-FERTILIZADORA CON UN SISTEMA MECATRÓNICO ADAPTADO PARA EL CONTROL DE LOS DOSIFICADORES
Authors: Torres-Sandoval Julio , Romantchik-Kriuchkova Eugenio , López-Cruz Irineo L. , López-Canteñs Gilberto de J. , De la O-Olán Micaela
Published: January 2021

Las máquinas sembradoras-fertilizadoras utilizadas en el campo mexicano usan sistemas mecánicos para el accionamiento de los dosificadores. En países desarrollados estos sistemas se están reemplazando por sistemas mecatrónicos implementados en máquinas de dosificación variable. Los sistemas mecatrónicos tienen la ventaja de que su desempeño no se afecta por las condiciones del suelo y cubierta vegetal, además de la facilidad para realizar los cambios de la dosis de aplicación de insumos, al permitir realizarlos de manera continua y en tiempo real. Sin embargo, tienen la desventaja de su elevado costo de adquisición. Este estudio presenta los resultados de prueba de laboratorio de un sistema mecatrónico desarrollado con hardware y software libre de bajo costo y adaptado a la sembradora-fertilizadora Modelo LC-U-N del fabricante Sembradoras del Bajío S. A. de C.V. El dosificador de semilla se probó con semilla de maíz, bajo el estándar de la banda engrasada descrito en la norma ISO 7256-1:1984. Los resultados muestran buena calidad de distribución de la semilla a frecuencias de rotación del disco semillero de 0.524 a 2.199 rad s-1, al obtener índices de calidad de alimentación ≥ 90 %, pérdida de semilla y de multiplicidad inferiores al 6 % y precisión < 18 %. Los dosificadores de fertilizante y pesticida se probaron con base a la norma NMX-O-222-SCFI-2004, con fertilizante comercial UREA, al utilizar cinco frecuencias de rotación en el intervalo de 0.524 a 3.77 rad s-1 y de 1047 a 14,661 rad s-1, respectivamente, con diferentes aberturas de la compuerta de salida. Para el caso del dosificador de fertilizante se obtuvo una dosis de aplicación de 3 a 562 kg ha-1 con el mejor desempeño al utilizar aberturas de la compuerta ≤ 50 %, mientras que el dosificador de pesticida presentó un desempeño excelente, con el cual se obtuvo una dosis de aplicación de 0.004 a 16.4 kg ha-1.
RESPUESTA FOTOSINTÉTICA DE LECHUGA HIDROPÓNICA A RELACIONES DE NO3-/NH4+ EN VERANO Y OTOÑO
Authors: Lara-Izaguirre Ana Y. , Rojas-Velázquez Angel N. , Ramírez-Tobías Hugo M. , Alcala-Jauregui Jorge A. , Méndez-Cortés Heriberto , Romero-Méndez Mauricio J.
Published: January 2021

La lechuga (Lactuca sativa L.) es un importante cultivo alimenticio y es cultivada en todo el mundo. Su rendimiento fotosintético y metabólico es dependiente de parámetros de luz y de temperatura. Por otro lado, la fuente del suministro de nitrógeno (N) a la planta se relaciona de manera directa con la eficiencia fotosintética; por este motivo la fotosíntesis es afectada por la disponibilidad de N y por la radiación. Con base en lo anterior, el objetivo del trabajo fue evaluar la respuesta fotosintética del cultivo de lechuga en hidroponía con relaciones nitrato/amonio (NO3-/NH4+) en verano y otoño. Las lechugas se cultivaron en un sistema hidropónico de raíz flotante. El diseño experimental fue completamente al azar, con arreglo factorial 4 x 2, cuatro relaciones de NO3-/NH4+ (100/0, 80/20, 65/35 y 50/50) y dos estaciones (verano y otoño), con un total de ocho tratamientos y 300 unidades experimentales (en cada estación). Se evaluaron las variables: eficiencia máxima del fotosistema II (Fv/Fm), eficiencia efectiva del fotosistema II (ФPSII), tasa de transporte de electrones (ETR), asimilación neta de CO2 (Pn), tasa de transpiración (E) y conductancia estomática (gs). Las condiciones ambientales del otoño promovieron un aumento en todas las variables de fotosíntesis. La relación 100/0 aumentó 17.5 % más ФPSII y 15.73 % más gs. La interacción estación verano con la relación 50/50 disminuyó la Fv/Fm a 0.78 y en ETR la 100/0 fue menor en un 41.76 %. La aplicación de NH4+ en dosis mayores al 35 % en la solución nutritiva disminuyó las variables de fotosíntesis en el cultivo de lechuga en verano. La reacción fotosintética asociada con crecientes proporciones de N amoniacal en la solución nutritiva es dependiente de la estación de cultivo (verano u otoño), al parecer asociada con la temperatura y radiación.
EXPRESIÓN DIFERENCIAL DEL COMPLEJO ARF8-IAA25-like-TIR1 DURANTE EL SÍNDROME POST-POLINIZACIÓN EN DOS GENOTIPOS DE VAINILLA
Authors: Hernández-Miranda Olga A. , Reyes-Mateos David A. , Campos Jorge E. , Sandoval-Zapotitla Estela , Herrera-Cabrera Braulio E. , Salazar-Rojas Victor M.
Published: January 2021

La transición de flor a fruto (TFF) es un proceso crítico en la reproducción de las angiospermas. Su regulación responde a un mecanismo hormonal que involucra genes de las familias ARF, Aux/IAA y TIR1; sin embargo, aún no se conoce con detalle su funcionamiento en plantas con síndrome post-polinización como las orquídeas. El conocimiento acerca de los procesos moleculares que dirigen la TFF permitirá atender problemáticas como la ’caída prematura de fruto’, que afectan al cultivo de vainilla a nivel global. Con el objetivo de describir el proceso de TFF en vainilla (Vanilla planifolia Andrews) se analizó, mediante qPCR, el nivel de expresión relativa (ER) de los genes VpARF8, VpIAA25-like y VpTIR1 durante 45 días después de la polinización (ddp), en un genotipo ‘tolerante a caída’ (CH-I) y otro ‘susceptible’ (CH-VI). Se realizó purificación de ARN, síntesis de ADNc y se cuantificó la ER. Los datos de expresión se analizaron mediante ANOVA de dos factores (genotipo y tiempo de desarrollo) y análisis de conglomerados tipo Heatmap (genes, genotipo, fase del desarrollo). Se detectaron diferencias significativas en los niveles de ER de los genes VpARF8 y VpTIR1 durante los 45ddp, sin variación entre genotipos; mientras que el gen VpIAA25-like presentó diferencias únicamente entre genotipos. En el análisis multivariado se distinguieron dos perfiles de expresión que pueden estar relacionados con las etapas de polinización y fecundación en vainilla, mismas que ocurren en momentos distintos debido al síndrome post-polinización. En el genotipo CH-I la fecundación ocurre alrededor de 45ddp, mientras que en el genotipo CH-VI no se observa. Los tres genes presentaron cambios en los niveles de expresión durante el síndrome post-polinización en CH-I, pero no en CH-VI, lo que sugiere que el fenómeno conocido como ’caída prematura de fruto’ es un efecto genotipo dependiente, definido por una diferencia en el mecanismo de regulación del metabolismo de auxinas.
ROTACIÓN DE TRIGO, MAÍZ Y CÁRTAMO EN LABRANZA DE CONSERVACIÓN vs. LABRANZA TRADICIONAL
Authors: Borbón-Gracia Alberto , Lugo-García Gabriel A. , Reyes-Olivas Álvaro , Valenzuela-Herrera Víctor , Sauceda-Acosta Carlos P.
Published: January 2021

La rentabilidad de los granos básicos requiere mejorar en el noroeste de México; una opción para lograrlo es reducir el laboreo mecánico y el empleo de la rotación de cultivos, pero es necesario evaluar el rendimiento y la relación costo-beneficio en labranza de conservación (LC) y en rotación de cultivos. El objetivo del presente estudio fue evaluar la LC con rotación entre trigo (Triticum durum Desf.), maíz (Zea mays L.) y cártamo (Carthamus tinctorius L.), comparada con el sistema de labranza tradicional (LT) durante los ciclos otoño-invierno 2014-2015, 2015-2016 y 2016-2017, en el sur de Sonora, México. Se utilizó la variedad de trigo CIRNO C2008, el híbrido de maíz Garañón y la variedad de cártamo CIANO-OL. La siembra del trigo fue a doble hilera, con una densidad de 100 kg ha-1 de semilla, el maíz y cártamo a hilera sencilla con 100,000 y 170,000 semillas ha-1, respectivamente. Se utilizó un diseño experimental completamente al azar con arreglo factorial, los tratamientos fueron los cultivos trigo, maíz y cártamo con y sin rotación entre sí en LC, y sin rotación en LT. La parcela experimental constó de ocho surcos de 0.8 m de ancho por 100 m de largo. Se midió altura de planta, días a floración, días a madurez fisiológica, peso de 1000 granos y rendimiento de grano. El rendimiento de trigo/cártamo en LC (7255 kg ha-1) fue superior a trigo/trigo en LT (P ≤ 0.05). El rendimiento de maíz/maíz en LT y maíz/trigo en LC fue estadísticamente igual (P ≤ 0.05), pero maíz/trigo en LC mostró mayor relación beneficio-costo. Cártamo/trigo en LC, con 2763 kg ha-1, fue estadísticamente superior (P ≤ 0.05) a cártamo/cártamo en LT. Los rendimientos de trigo, maíz y cártamo en LC fueron favorecidos por la rotación de cultivos, lo cual mejora la relación beneficio-costo y la utilidad.