bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of COVID-19 on People Suffering with Epilepsy
Authors: Sureka Rajendra K. , Gaur Vikas , Gupta Medha
Published: October 2020

Background:

Epilepsy is one of the most common problems in neurology clinical practice and currently we are in the midst of the coronavirus outbreak. The coronavirus pandemic is an epidemiological and psychological crisis, which is likely to affect persons with epilepsy.

Objectives:

This study was designed to evaluate the impact of COVID-19 pandemic on patients with epilepsy and effects on their mental health.

Materials and Methods:

This was a cross-sectional web-based survey carried out at the department of Neurology at a tertiary care hospital. A questionnaire was designed in the local language using Google Forms to assess basic knowledge regarding epilepsy, coronavirus, effects of COVID-19 and lockdown on epileptic patients and also effects on their mental health. The link to the online survey was distributed via WhatsApp messenger to epilepsy patients.

Results:

One hundred fifty-six cases were enrolled with 69.1% were below 34 years of age and male: female ratio was 1.2:1. Only 34.3% of the participants were employed and 50% of patients had an income of less than Rs. 3000 per month. Of the patients enrolled, 20.5% reported the “devil” and superstitions as a cause of epilepsy and only 10% of patients thought that tantric (holy priest) could treat the disease better than doctors. 53.8% of patients worried about getting COVID-19 and could not stop thoughts about being infected by coronavirus bothering them. 30.3% patients had increased seizure frequency during COVID-19 pandemic, of which the most common reason was that they forgot to take regular antiepileptic drugs (22.7%) or they had faced difficulty in obtaining medicine due to lockdown (12.1%). During the pandemic, 17% of patients reported depression symptoms and another 21% reported anxiety symptoms.

Conclusion:

The current COVID-19 pandemic negatively affected patients with epilepsy and increased seizure frequency, depression, anxiety, unemployment, and financial difficulty in obtaining medication.
Horizontal Mobility of Heavy Metals from Dumpsite in North Central States, Nigeria
Authors: Bala J.D. , Musa J.J. , Mustapha H.I. , Yerima I.Y. , Sunday D.E. , Musa A.P.
Published: October 2020

Industrialization and population growth has lead to the introduction of toxic substances into the environment as waste from manufacturing  processes. This study describes the horizontal mobility of this waste containing heavy metals from dump sites to the surrounding environment of North Central state, Nigeria. Soil samples were collected within the dumpsites and the immediate surrounding soil at distance of 10m and 20m away to assess the migration and potential bioavailability of Cr, Fe, Mn, Pb, Zn, Cu and Al. Total concentration of the heavy metals and their fractionation were determined. The results indicate that heavy metals are more concentrated in the uppermost layer with significant migration down the slope, thereby posing a threat to groundwater quality. In the fractions, the concentrations of the metals follow this sequence: Mn>Fe>Cu>Zn>Cr>Al. The mobility factors of the heavy metals are significantly high indicating high potential mobility and bioavailable forms of these heavy metals. The high concentrations of the heavy metals particularly Cr, as observed in the study is as a result of anthropogenic activities on enrichment of natural soil with bioavailable heavy metals. Consequently, there is a need to be cautious in the way waste that is generated from heavy metals sources is added to natural soil.

Key words: Dump site; Environment; Heavy metals; Soil; Waste
Toxicological studies of silver nanoparticles synthesized from Calopogonium mucunoides aqueous leaf extract on Wistar rats
Authors: Adedeji A.S. , Kuta F.A. , Tijani J.O. , Adabara N.U.
Published: October 2020

Increasing usage of nanosilver (AgNPs) for biomedical purposes outstrips the handiness of safety evaluation studies. This study investigates oral toxicity of biogenic AgNPs (at 50, 75, 100 and 150 μg/kg) on rats. Results analysis revealed that C. mucunoides AgNPs improved dietary intake and body weight of rats. Level of serum total protein significantly increased 9.54±0.05, 8.31±0.06, 11.31±0.41, 10.48±0.65 g/dL compared to control 6.43±0.55 g/dL while serum AST significantly reduced to 0.05±0.00 and 0.10±0.02U/L at 50 and 75 μg/mL. AgNPs did not significantly (P ˃ 0.05) altered serum chloride, urea, ALT and creatinine relative to the control. However, serum potassium (10.74±1.86 mmol/l) significantly decreased (P < 0.05) to 3.11±0.71, 3.12±2.50 4.64±1.47, 5.79±1.30mmol/L respectively. There was also a significant (P < 0.05) dose dependent upsurge in platelets (618.50±48.79, 743.50±17.68, 763.50±10.60 and 843.50±24.75) and MCV (49.50±0.71, 52.50±0.71, 53.50±0.71 and 56.00±4.24) compared to the control (617.50±79.90 and 43.00±0.00) respectively. The haemoglobin, PCV, MCHC, MCH, RBC, WBC, lymphocytes, monocytes, eosinophils and basophils values were not different (P ˃ 0.05) from the control. Results obtained suggest that AgNPs is relatively safe, although it altered serum total protein and potassium concentrations, no rat died due toxicological effect.

Keywords: Alterations, nanosilver, toxicity, upsurge.
Alternative method of reducing sugars determination in some selected fizzy drinks and fruits by chromic acid reagent
Authors: Olajide Mustapha A.
Published: October 2020

Chromic acid reagent as an alternative colorimetric method for the quantitative determination of reducing sugars and ascorbic acid in some selected fizzy drinks: Seven Up, Limca, Mirinda, Cocoa-Cola, Fanta, Pepsi Cola, Maltina, Guinness Malt, Hi-Malt and Maltonic) and fruits: pineapple (Ananas cosmoses), sweet orange (Cimifi sinensis), grape fruit (Dints paradise) and tangerine (Citrus reticulate) has been studied. Chromic method involves sugar solution of about 1% concentration. treated with an equal volume of concentrated nitric acid and a few drops of a 5% solution of potassium dichromate was added, a blue colour develops in less than a minute in the cold and the absorbance taken in a Spectronic 20D Spectrophotometer at 560 um. Results obtained from the simple chromic acid as test method compares well with those obtained from the titrimetric methods of Association of Official Analytical Chemists (AOAC, 2012) and Pearson (1991) as control, with negligible variations. Apart from being a very powerful oxidizing agent, its reaction with monosaccharide, disaccharides and ascorbic acid are less-time consuming, showed distinct colour development and its easy preparation, made chromic acid reagent a faster, better and suitable alternative method for the quantitative determination of reducing sugars and ascorbic acid in routine analyses of foods.

Keywords: reducing sugar, ascorbic acid, chromic reagent.
Software defect prediction: A multi-criteria decision-making approach
Authors: Balogun A.O. , Bajeh A.O. , Mojeed H.A. , Akintola A.G.
Published: October 2020

Failure of software systems as a result of software testing is very much rampant as modern software systems are large and complex. Software testing which is an integral part of the software development life cycle (SDLC), consumes both human and capital resources. As such, software defect prediction (SDP) mechanisms are deployed to strengthen the software testing phase in SDLC by predicting defect prone modules or components in software systems. Machine learning models are used for developing the SDP models with great successes achieved. Moreover, some studies have highlighted that a combination of machine learning models as a form of an ensemble is better than single SDP models in terms of prediction accuracy. However, the efficiency of machine learning models can change with diverse predictive evaluation metrics. Thus, more studies are needed to establish the effectiveness of ensemble SDP models over single SDP models. This study proposes the deployment of Multi-Criteria Decision Method (MCDM) techniques to rank machine learning models. Analytic Network Process (ANP) and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) which are types of MCDM techniques are deployed on 9 machine learning models with 11 performance evaluation metrics and 11 software defects datasets. The experimental results showed that ensemble SDP models are best appropriate SDP models as Boosted SMO and Boosted PART ranked highest for each of the MCDM techniques. Besides, the experimental results also validated the stand of not considering accuracy as the only performance evaluation metrics for SDP models. Conclusively, more performance metrics other than predictive accuracy should be considered when ranking and evaluating machine learning models.

Keywords: Ensemble; Multi-Criteria Decision Method; Software Defect Prediction
Foreign direct investment, financial development and economic growth in Asian developing countries
Authors: Phuc Nguyen Van , Anh Nguyen Thuc Duy
Published: October 2020

This research investigates the role of domestic financial development in enhancing the positive effects of foreign direct investment (hereafter, FDI) on economic growth in Asian developing countries. In other words, we examine whether countries with a better domestic financial system can utilize FDI more efficiently. The empirical analysis uses balanced panel data of 24 Asian developing countries in the period 1995-2009. This research applies the various models and techniques in panel data regression. Linear static models for panel data, including constant coefficients model or pooled regression model (POOLED), fixed effects regression model (FEM) and random effects regression model (REM) are employed. We analyze all models and employ several kinds of test including poolability test, Hausman test, LM test, fixed effects tests and Wald tests to select the most appropriated estimated model. The research findings show that FDI alone does not have direct effect on economic growth but does have when combined with financial development. Well-developed domestic financial markets promote the process of technological diffusion associated with FDI in Asian developing countries. Therefore, FDI and domestic financial development are complementary in increasing the rate of economic growth in the region. There is a threshold level of domestic financial development above which FDI starts to have positive impacts on economic growth.
The impact of research results on the research expenditure at The U.S. Universities
Authors: Phuong Nguyen Van
Published: October 2020

The research spending at universities has become an integral part of development strategies among universities in the world. It is also used as one of key indicators to evaluate university ranking. Therefore, many studies have emphasized on the quality of research results and the impact of technology spillovers from universities to industry. However, the previous empirical evidence is ambiguous as well as it has not identified either the necessary time for an inventor to recoup the initial investment or the linkage between startup and research spending. To fulfill unsolved problems from previous studies, the paper focuses on finding the determinants impacting on the research expenditure at universities by employing a panel of the U.S universities from 1998 to 2004. Specifically, we implement the regression model with differentiating both the level effects and the rate effects of patent applications and licensing income, the estimatedresults imply that an increase in either the number of patent applications or licensing income reduces the short-term research expenditure but increases the long-term rate of research spending growth of average universities. Moreover, we also find that the more startup firms the inventors pursue, the more research spending they receive.
Oaxaca - blinder decomposition extended for the non-linear model to identify the ownership gap in the exit rate
Authors: Ha Nguyen Minh
Published: October 2020

The purpose of this research is to identify factors to explain the gap in exit rate between state and non-state firms in Vietnam. With a sample of 7,962 Vietnamese firms and using the Oaxaca-Blinder decomposition extended for non-linear models, the research finds out that a very large part of the ownership gap in exit rate between state and nonstate firms cannot be explained by the included covariates, but it is almost explained by

the effects of differences in the coefficients of covariates. In particular, the differences in coefficients of covariates of initial assets, the industrial sector (mining, construction and manufacturing industries), and the service sector considerably increase the ownership gap in exit rate, but the difference in the coefficient of initial employment reduces the ownership gap in the exit rate. Moreover, differences in explanatory variables between state and non-state firms explain a very small part of the ownership gap in exit rate. This

means that an estimate of the reduction in state and non-state firms’ exit rates (resulting from giving non-state firms the same characteristics as state firms) is very small. The differences in coefficients have a much greater impact on differences in exit rates than characteristics that may be due to existing discrimination between state and non-state firms.
Hospitalization issues in the public health care system: Evidence from Vietnam
Authors: Phuong Nguyen Van
Published: October 2020

This paper aim to build a theory model to generalize the health care market and find the solution for the hospitalization issues in the public health care system in Vietnam. Specifically, the results indicate that increased quality improvement and reduced waiting time for patients within a hospital are able to solve if two-price tariffs are allowed to implement in the state hospitals. Additionally, by exploring the two-wave Vietnamese Household Living Standard Survey conducted in 2004 and 2006, this paper also investigates the impact of the new health insurance policy on a number of hospital visits.
The deterioration of weakly vertical linkages in tra catfish industry in An Giang Province, Vietnam
Authors: Phuong Nguyen Van , Van Bui Thanh Thuy , Hien Huynh Thi Ngoc
Published: October 2020

This study analyzes the vertical linkage effectiveness between fish farmers and processing companies on the mutual beneficial relationship, knowledge transfer, quality standards, embedded services, and payment before the United State (US) Department of Commerce has decided to impose new rates of antidumping taxes on tra (Pangasius) fish fillets imported from Vietnam. After conducting the first survey of 70 fish farmers and five in-depth interviews with directors of processing enterprises, representatives of provincial authority, and experts in the field during March and April of 2012 in An Giang province, Vietnam, we found that the mutual beneficial relationship was the most influent factor to vertical linkage effectiveness. However, after new rates of antidumping duties were imposed, we conducted the second survey of 17 in-depth interviews with 12 fish farmers, four local officers and one expert during April and June of 2013 in An Giang province, and recognized that almost all vertical linkages with processing companies to export to the US market have been deteriorated and dispersed.
Entrepreneurship and economic development: A literature review
Authors: Phuc Nguyen Van
Published: October 2020

This paper makes a comprehensive review of entrepreneurship on economic development in economic theory. It indicates how entrepreneurship is crucial for economic development. The role of entrepreneurship on economic development originated from different understandings on the nature of economic system. It is argued that the role of the entrepreneur has been moved out of the neoclassical model because a crucial assumption of the model is that decision-making merely involves marginalist calculation to optimise production, based upon public information supplied by the price system. The explanation for the phenomenon of economic development depends on how we understand the nature of the market process. In this respect, the economics of entrepreneurship is different from mainstream economics. For mainstream economics, the market is generally characterised by equilibrium. For the economics of entrepreneurship, the market process is characterised by disequilibrium. The review of literature indicates that entrepreneurship has different essential features that all are critical to economic development

and the market process. They are Kirzner’s arbitragers or Schumpeter’s innovators. They are Knight’s uncertainty-bearing people. They assume managerial or leadership roles and thus function as the main allocators of scarce resources in the economic system as identified by Baumol and Casson. Entrepreneurship is a solution to X-inefficiency, by motivating efforts within firms as argued by Leibenstein. All this has important implications for economic development. Millions of business decisions made by numerous entrepreneurs daily affect an economy a great deal. The pace of economic development ultimately depends on such endeavour

of numerous entrepreneurs. It is normally believed that the lagging behind of many developing countries lies in their lack of entrepreneurship. The policy implication is that, in order to have good economic development, governments should create a favourable environment for entrepreneurs to carry out above-mentioned functions in the economy.
Identifying the key factors and proposing a roadmap for successful lean transformation in Vietnamese manufacturing firms
Authors: Hung Bui Nguyen , Luong Le Phuoc , Nguyen Nguyen Thi Duc
Published: October 2020

This study is conducted to identify the key factors and propose a roadmap for successful lean transformation in Vietnamese manufacturing firms. Eight managers of two companies having successful lean performances and two lean experts from university and consulting company are invited to participate in semi-structured interviews to verify key factors of a successful lean transformation as well as to promote a lean roadmap with tools used for lean transformation in the context of Vietnam. The research results show that 10 key factors promoting a successful lean transformation are Role of management, Involvement and Commitment to change, Balanced scorecard implementation, Corporate vision and values, Corporate culture of change, Persuasive situation for change, Change projects, KPI application, Lean consultants, and Stakeholder communication. The respondents also adopt a roadmap for a successful lean transformation in Vietnamese companies including 3 phases (preparation, implementation, maintenance and improvement) in which 5S, Visual Control, and Work Standardization are the three most remarkable tools for lean transformation.
Factors of quality management system influencing organizational performance: A study of pharmaceutical factories getting GMP certificate in Vietnam
Authors: Loan Nguyen Thuy Quynh
Published: October 2020

A study objective is to identify key factors of QMS (Quality Management System) influencing the organizational performance in pharmaceutical factories getting GMP (Good Manufacturing Practices) certificate. The original research model consists of eight independent factors (leadership, process management, education and training, supplier management, customer focus, employee involvement, product design, and continuous improvement) and three dependent factors related to organizational performance (productivity, product quality and customer satisfaction). The study collects 265 suitable questionnaires filled by middle managers or the top managers of the pharmaceutical factories getting GMP in Vietnam. The results identify key factors of QMS as leadership, employee involvement towards customer focus, and continuous improvement towards product design have positively impact to organizational performance that is represented by productivity and product quality, customer satisfaction. The study thensuggests managerial implications to top management of pharmaceutical factories in improving performance through enhancing key factors of QMS implementation.
Factors affecting Chinese tourist’s loyalty towards Ho Chi Minh City - A mediation analysis of tourists’ perceived value
Authors: Khuong Mai Ngoc , Khai Nguyen Tran Nguyen , Dao Do Ai
Published: October 2020

The purpose of this research was to examine empirically the causal relationships among push factors, pullfactors, risk perception, tourists’ perceived value and loyalty of Chinese tourists travelling to Ho Chi Minh City. A survey was conducted investigating 470 Chinese tourists to collect the primary data. As a result, Chinese tourists’ loyalty towards Ho Chi Minh City could be predicted by some of their push motivation, pull motivation and their perceived value about the trip or tourists’ services received. Consequently, business organizations and tourism companies should consider the crucial roles of push and pull factors to attract more potential repeated visitors and increase their perceived value and loyal to Vietnam, especially to Ho Chi Minh City in the near future.
What sources of finance constrain Vietnamese listed firms?
Authors: Hau Le Long
Published: October 2020

This study is to investigate the sources of finance imposing the constraints on Vietnamese listed firms, after the introduction and rapid growth of the equity markets and the privatization wave that started since 1992. Using accounting data of listed firms on the Vietnamese stock markets, we find that listed firms are financially constrained with respect to both external funding sources, equity and long-term debt finance. Particularly, state-owned firms do exhibit higher sensitivity coefficients of equity than private firms, albeit with a non-statistically significant difference. For bank loan financing, we notice that large (HOSE listed) state-owned firms show a sensitivity that is three times the sensitivity of the private firms. The smaller HNX listed firms, however, show the reverse result, the private firms have a sensitivity coefficient that is twice as large as the one for the state-owned firms.
Determinants of profit efficiency among peanut farming households in Tra Vinh province, Vietnam
Authors: Dang Nguyen Huu
Published: October 2020

This study is aiming to identify profit efficiency and its determinants among peanut farming households in Tra Vinh province, Vietnam, based on the data collected from 182 peanut farming households in three districts of Tra Vinh province. The Cobb-Douglas stochastic frontier profit function incorporating profit inefficiency effects was employed to analyze the data, using the Frontier 4.1. The results revealed that the profit efficiency was ranged between 29.80 to 96.76 percent, an average of 59.06 percent. Significant factors that were found negative affect the peanut farm profit were prices of fertilizer, pesticide, wage rate; whereas, the price of seed and land area (fixed factor) were found negative effect the peanut farm profit. Significant determinants that were found positive effect the profit efficiency of peanut farmers were gender, education attainment, peanut farming experience, farm size, credit access, training, and farmer’s association membership.
A Mosaic of Vigna hosei (Craib) Back, a Common Weed in Puerto Rico
Authors: Enrique Pérez J. , Bird Julio
Published: October 2020

A mosaic virus of Vigna hosei (Craib) Back is described. The virus was transmitted by mechanical means to several varieties or selections of Phaseolus vulgaris and to Cassia occidentalis and P. lathyroides. It was transmitted to seven different plant species by means of Aphis craccivora. It resembled somewhat the mosaic virus of V. repens on the basis of symptoms produced on several bean varieties and selections.
Preparation and Acceptability of Banana Nectar
Authors: Hernández I.
Published: October 2020

A method was developed to prepare commercially banana nectar of good quality and high acceptability using banana pulp puree as a base. The pulp puree was prepared from hand-peeled ripe fruits processed at pH 4.00, packed in plastic containers and frozen. It was found that the best formulation for the nectar consisted of a 15-percent pulp content at pH 4.00. During the final processing, the addition of a cellulose gum stabilizer at the rate of 1 pound per 100 gallons of the nectar and the homogenization of the nectar prior to pasteurization at 190° to 200° F. prevented the separation of the pulp. The nectar thus prepared showed a shelf-life of more than 6 months when kept in tin cans at 85° F. A consumer acceptance test in which 5,000 tasters evaluated this product showed an acceptance of 93 percent (76 percent liking it very much and 17 percent moderately).
Storage of Green Plantains
Authors: Hernández I.
Published: October 2020

Studies were made of green plantain behavior when stored under various conditions to develop the best method of prolonging their shelf life without affecting their overall quality and processing characteristics. Freshly harvested green plantains start to ripen in about 7 days, reaching full ripeness 2 days later, when kept under room conditions at temperature of about 85° F. When stored in refrigerated chambers, plantains from the Guayamero and Maricongo cultivara remain green for 12 days, at which time signs of chilling damage begin to appear. However, the quality of plantains stored in these refrigerated chambers at 45° and 55° F. with relative humidities of 86 to 88 percent are definitely affected. At 45° F. a marked hardening of the fruits was observed and at 55° F., signs of false ripening appeared, impairing the quality of the produce. Shelf life of green plantains may be successfully prolonged, however, when thiobendazole-treated fruits are stored in sealed polyethylene bags containing an ethylene absorbent (about 200 g. of Purafil). TBZ was used in a 200-p.p.m. concentration to control mold growth. By using these combined techniques plantains were kept perfectly green for 25 days at room temperature (85° F.) and for 55 days under refrigeration (55° F.). This method had no detrimental effect on the stored fruit, as shown by the sensory evaluations of two processed products prepared from the stored green plantains at various intervals throughout the study. Tasters rated the samples as good or superior to similar products prepared from freshly harvested green fruit.
Variation in Chemical Composition of Dracaena sanderiana Leaves as Influenced by Leaf Maturity and Shade Intensity
Authors: Rodríguez Saulo J. , Rivera-López Carlos , Santiago Alejandro
Published: October 2020

Seventy-five tops of D. sanderiana were grown and harvested, 15 from each of five different shade intensities. The leaf blades of each top were separated as to position in the stem. Composite samples of the leaves having the same numbered position in the 15 tops at each level of shade were chemically analyzed for nitrogen, phosphorus, potassium, calcium, and magnesium. Leaf position definitely influenced the chemical content of the leaves. The immature leaves showed lower values of nitrogen, calcium and phosphorus. The values increased with age. There was a reduction in the chemical content farther down in the stem. Leaf potassium was high in the young leaves with a definite decrease with age, until it became stabilized or it increased in the old leaves. Leaf phosphorus did not seem to vary with age. The shade intensities did not seem to affect the leaf nutrient content markedly, except potassium and magnesium to some extent, expecially in immature leaves. Functional relationships were established for leaf position and leaf nutrient content, with a high percentage of explanation of the variability. It can be concluded that leaf samples midway in the stem are suitable for analysis. Leaves of the 2d, 3d or 4th position will possibly reflect the nutritional status of the plant.
Evaluation of Seven Forage Grasses at Two Cutting Stages
Authors: Sotomayor Ríos A. , Acosta Matienzo A. , Vélez Fortuño J.
Published: October 2020

Seven forage grasses, i.e., Tanner (Brachiaria cf. mutica), a bermuda grass selection (Cynodon dactylon var. coursii), glabrous Signal (Brachiaria brizantha), Signal (Brachiaria brizantha), Congo (Brachiaria ruziziensis), Star (Cynodon nlemfuensis var. nlemfuensis) and Pangola (Digitaria decumbens) were cut at a 60-day harvest interval and at the optimum stage for harvest during a 2-year period at the Gurabo Substation. It was considered that plants had reached the optimum stage for harvest when flowering and yellowing of leaves at the basal parts of the plant began to appear and the grasses had attained a reasonable forage volume as compared to adjacent plots harvested every 60 days. At the 60-day harvest interval, the top yielder was the glabrous Signal; this grass produced 72.78, 19.85 and 1.40 tons of total green, dry forage, and crude protein per acre per year, respectively. Signalgrass was second best with 69.93,16.87 and 1.20 tons of green, dry forage and crude protein per acre per year, respectively. At the optimum stage for harvest, the top yielder in terms of total green forage per acre per year was Congograss with 70.40 tons. The best dry forage and crude protein yielder was glabrous Signal with 18.84 and 1.54 tons per acre per year, respectively. Pangolagrass was second best in terms of total green and dry forage per acre per year with 69.90 and 17.30 tons, respectively. The green forage yields of the grasses studied, except Tannergrass, were similar when cut at the 60-day harvest interval as compared to the optimum stage for harvest. The annual dry forage yield also was similar at the two cutting stages, except Tannergrass and C. dactylon var. coursii. Significantly higher protein yields were obtained at the optimum stage for harvest in all forages with the exception of Signalgrass. Glabrous Signal (Brachiaria brizantha), USDA PI 255346, was the top dry forage yielder of the seven grasses studied. This grass produced about 20 tons of dry forage (73 tons of green forage) containing 7.1 percent of protein and about 19 tons of dry forage (69 tons of green forage) containing 8.2 percent of protein, at the 60-day harvest interval and at the optimum stage for harvest, respectively.
Shell-Life Study of Farm Lisbon Yam (Dioscorea alata) Chips
Authors: Rodríguez-Sosa E. J. , Cruz-Cay J. R. , González M. A. , Martin F. W.
Published: October 2020

Yam chips of good quality were prepared from the Farm Lisbon variety (D. alata). Samples were packed using three different types of storage containers, i.e., vacuum-packed tin cans, nitrocellulose-coated 195-yield, double cellophane bags, and polyvinylidene chloride-coated 210-yield, double cellophane bags. Yam chips packed in vacuum-packed tin cans had a longer shelf-life than those packed in the two other types of containers. Of the three types of frying media, lard proved best in terms of its effect on sensory qualities.
The Syrphidae of Puerto Rico
Authors: Telford H. S.
Published: October 2020

This paper presents results of a taxonomic investigation of the family Syrphidae of the order Diptera in Puerto Rico. A total of 58 species included in 11 genera are presently recorded as a result of synonymy, new records, and descriptions of the following four new species: Baccha (Baccha) martorelli, Baccha (Ocyptamus) medina, Baccha (Baccha) neoparvicornis and Baccha (Ocyptamus) vockerothi. Keys are given for the identification of the reported genera and for most of the recorded species.
LIRIOMYZA MUNDA FRICK (DIPTERA: AGROMYZIDAE) ATTACKING BEANS AND CUCUMBERS IN PUERTO RICO
Authors: Pérez Pérez Rafael
Published: October 2020

LIRIOMYZA MUNDA FRICK (DIPTERA: AGROMYZIDAE) ATTACKING BEANS AND CUCUMBERS IN PUERTO RICO
Título en español.
Authors: Fernando Abruña  , José Lozado
Published: October 2020

Se determinó el efecto de la época del año en la productividad de 13 variedades de arroz mediante siembras mensuales realizadas durante un año en la Subestación de Gurabo. Las variedades Sinaloa que son semi-enanas y tardías, y producen granos de tamaño largo mediano produjeron los más altos rendimientos con un promedio de 4,910 libras de arroz en cáscara por acre por cosecha. La producción de las 13 variedades de arroz no fue afectada apreciablemente por la época del año. Los datos obtenidos demuestran que en la región húmeda de Puerto Rico pueden producirse dos cosechas de arroz, lográndose una producción total de unas 5 toneladas de arroz en cáscara por acre al año bajo condiciones similares a los de estos experimentos.
Título en español.
Authors: H. D. Dubey  , Rita L. Rodríguez
Published: October 2020

Durante 18 meses se estudiaron, en condiciones de laboratorio, los cambios producidos en los microorganismos presentes en el suelo arcilloso ácido laterítico Humatas y en el alcalino y fértil San Antón lómico, ambos incubados a 23° ± 1° C. después de haber recibido aplicaciones de 2,4- dicloro-(o-cloroaniline)-s-triazina (Dyrene) y etileno bisditiocarbamato de manganeso (Maneb) en concentraciones de 0, 60, 240 y 960 p.p.m. En general, el número de bacterias aumentó y el de actinomicetos y hongos disminuyó, especialmente a las concentraciones más altas de los agentes químicos. El aumento en el número de bacterias cesó a los 10 meses, excepto en el caso del Maneb a 960 p.pm., cuando el incremento persistió por más tiempo. Parecen ser las bacterias los principales microorganismos responsables de la degradación de estos fungicidas en el suelo. El Maneb produjo cambios cuantitativos y cualitativos en la población de hongos. En cuanto a la reacción al tratamiento químico, se notaron diferencias entre los microorganismos de uno y otro suelo. La inoculación con suelo fresco neutralizó la inhibición de los microorganismos.
Título en español.
Authors: Dubey R. Woodbury  , G. L. Spain  , Rita L. Rodríguez
Published: October 2020

Se llevó a cabo en Puerto Rico una búsqueda por legumbres nativas tropicales noduladas de posible utilidad agrícola. Se hallaron 49 de estas especies de legumbres, de las cuales 13 eran noduladas y no se habían informado antes. Se describen los nódulos rizóbicos de las 49 especies y, además, se presentan observaciones agronómicas sobre el hábito de crecimiento de las plantas y sus habitats.
EFFECT OF BORON AND ZINC APPLICATIONS ON YIELDS OF INTENSIVELY MANAGED PLANTAINS GROWING ON A STEEP ULTISOL
Authors: Servando Silva  , José Vicente-Chandler
Published: October 2020

EFFECT OF BORON AND ZINC APPLICATIONS ON YIELDS OF INTENSIVELY MANAGED PLANTAINS GROWING ON A STEEP ULTISOL
Título en español.
Authors: Julio Bird  , Josefina Sánchez  , Rita L. Rodríguez  , Amelia Cortés-Monllor  , Walter Kaiser
Published: October 2020

Un virus (BVBMV) capaz de provocar ligeros síntomas de mosaico y el bandeado de las nervaduras en varias especies de plantas fue aislado de habichuelas (Phaseolus vulgaris L.) cultivadas en un predio experimental. El virus se transmitió por medios mecánicos y a través de varias especies de áfidos. Los resultados obtenidos de estudios realizados sobre la transmisibilidad, gama de plantas hospedadoras, serología y propiedades físicas del referido agente viroso indican que se trata de una cepa, posiblemente nueva, del mosaico común del pepinillo (CMV).
Título en español.
Authors: Reinaldo Calero  , Luis Muler Manzanares  , George E. Pringle
Published: October 2020

En este estudio se presentan los cambios que han ocurrido en el nivel y estándar de vida de las familias de agregados y parceleros. Para computar los índices característicos del estilo material de vida deseado o logrado por ambos grupos en un período determinado, se utilizaron técnicas de la función discriminatoria. Los análisis demostraron que se han registrado cambios importantes en sus niveles de vida, pero las mejoras que se evidencian son más pronunciadas en las familias de parceleros que en las de agregados. Los análisis también identificaron etapas intermedias en el proceso del nivel de vida y demostraron que la etapa en que se encuentran los agregados está en una fase más atrasada que la de los parceleros. Una conclusión importante que se desprende de este estudio es que la Administración de Programas Sociales ha tenido éxito en establecer condiciones propicias al mejoramiento de los niveles de vida de los parceleros.
Título en español.
Authors: K. Dale Ritchey  , Richard H. Fox
Published: October 2020

Para comprobar si es posible corregir mediante el abonamiento y el riego adecuado la infertilidad que se ha informado respecto a algunos subsuelos, se llevaron a cabo experimentos con maíz en un invernadero. Se encontró que el subsuelo expuesto de un suelo de la serie Nipe (Acrorthox típico; arcilloso, oxídico e isohipertérmico) era tan productivo como un suelo superficial de la serie Carreras (Tropohumult ácuico; arcilloso, caolinítico e isohipertérmico) cuando se le añadieron N, K, elementos menores y 600 ppm de P, y los tiestos se regaron por medio de mechas. El subsuelo Carreras, cuando se encaló y se abonó con N, K, 300 ppm de P, 100 ppm de Mg y 36 ppm de Zn fue tan productivo como la capa superficial, a pesar de contener solo una tercera parte de la materia orgánica. En un estudio comparativo entre ocho suelos superficiales y subsuelos se observó que los rendimientos de un suelo superficial encalado, bien abonado y regado adecuadamente de la serie Los Guineos (Tropohumult epiácuico humóxico; arcilloso, caolinítico e isotérmico); uno superficial de la serie Carreras; otro superficial de la serie Piña (Haplorthox psaméntico; arenoso e isohipertérmico); un subsuelo Los Guineos; otro subsuelo de la serie Piña; y uno superficial de la serie Catalina (Haplorthox tropéptico; arcilloso, oxídico e isohipertérmico) no eran significativamente diferentes. Sin embargo, el rendimiento del menos productivo de los dos subsuelos Catalina solo fue 64 por ciento del rendimiento del suelo superficial Los Guineos. Pero al añadírsele Zn y un poco más de 1,000 ppm de P, el rendimiento de ambos suelos en invernadero fue casi igual. Para determinar la cantidad óptima de P que debe aplicarse en condiciones de campo será necesario llevar a cabo experimentos de campo. Se concluyó que la productividad de los suelos superficiales y los subsuelos de los Ultisoles y Oxisoles que se estudiaron en tiestos en invernadero puede elevarse al mismo nivel alto si se abonan con minerales (incluyendo Zn y aplicaciones elevadas de P), se encalan y se riegan adecuadamente.
Título en español.
Authors: Raúl Pérez-Escolar  , J. Juárez, Jr.  , J. A. Bonnet  , M. A. Lugo López
Published: October 2020

En este artículo se presentan los datos obtenidos de un estudio exploratorio sobre algunas de las propiedades físicas de los suelos orgánicos del área de Caño Tiburones, el área más grande de este tipo de suelos en Puerto Rico. Estos suelos son muy livianos y pueden retener grandes cantidades de humedad bajo condiciones en que prevalezcan presiones de 1/2 y 10 atmósferas. El volumen de agua disponible para el desarrollo de las plantas es bajo debido al alto volumen que de ella retienen estos suelos al aproximarse a tensiones altas. Se sugiere que el manejo cuidadoso del nivel freático pueda ser la clave para aumentar la productividad y prolongar la utilidad de estos suelos para fines agrícolas.
Título en español.
Authors: J. Le Dividich
Published: October 2020

Se comparó el valor proteínico de la semilla de Vigna sinensis (raza M. 53) fresca y calentada con el de la harina de soya, ambas con un nivel de 14 por ciento de proteína, en pruebas de alimentación con ratos (macho de la rata). Al calentarse la semilla en un autoclave a 121° C por 15 minutos y añadírsele 0.15 por ciento de DL-metionina sintética a las dietas se mejoró el ritmo de crecimiento y la tasa de eficiencia del alimento y de la proteína. Además, el calentamiento de la semilla aumentó la digestibilidad y la retención del N. Cuando se calentó la semilla de Vigna sinensis y se suplemento con DL-metionina sintética su valor proteínico fue casi similar al de la harina de soya sin suplemento.
WHITE PEACH SCALE ATTACK ON TOON IN PUERTO RICO
Authors: Jacob L. Whitmore  , Silverio Medina Gaud
Published: October 2020

WHITE PEACH SCALE ATTACK ON TOON IN PUERTO RICO
Título en español.
Authors: J. Coward-Lord  , J. A. Arroyo-Aguilú  , O. García-Molinari
Published: October 2020

Se evaluaron muestras de las siguientes 10 yerbas forrajeras tropicales: Pangola, Digitaria decumbens; Congo, Brachiaria ruziziensis; Buffel, Cenchrus ciliaris; Guinea, Panicum maximum,' Jaragua, Hyparrhenia rufa; Pangola Gigante, Digitaria valida; "African Crab", Digitaria swazilandensis; Elefante Venezolana, Pennisetum setosum y Limpo, Hemarthria altissima, de 30 a 180 días de edad, tomadas a intervalos de corte de 30 días comenzando el 20 de agosto de 1970. Las yerbas se encontraban ya establecidas en parcelas con un área de 10 m2 en la colección de gramíneas del Colegio de Ciencias Agrícolas de la Universidad de Puerto Rico, localizada en Mayagüez. Se abonaron ligeramente con NH4NO3 a razón de 350 kg./ha. Se determinó el contenido de materia seca total (TDM). Se efectuaron determinaciones químico-analíticas de la proteína cruda (N X 6.25) (CP), la fibra cruda (CF), el extracto etéreo (EE) y la ceniza (A). El extracto libre de nitrógeno (NFE) se determinó como la diferencia entre 100 y la suma de la CP, la CF, el EE y la A. Los resultados se analizaron estadísticamente por el método de varianza. Se encontraron diferencias altamente significativas en todos los componentes con respecto a las especies forrajeras y a las edades de corte. Según fueron madurando las yerbas disminuyeron la CP, el EE y la A, mientras que la TDM, la CF y el NFE aumentaron con diferencias altamente significativas. El mayor cambio en valor nutritivo tuvo lugar entre los 30 y los 60 días de edad.
Título en español.
Authors: J. R. Cruz-Cay  , M. A. González
Published: October 2020

Se estudiaron algunas de las propiedades más importantes del almidón del ñame Florido (Dioscorea alata L.). El almidón contiene un 34 porciento de amilosa, el gránulo es de forma ovalada y tiene un diámetro de 31 µm, excediendo ambos los valores informados en la literatura. La viscosidad del almidón aumentó durante todo el proceso de cocción y enfriamiento. El almidón no exhibió un punto de viscosidad máximo, lo cual refleja la estabilidad del gránulo hinchado.
Título en español.
Authors: Niilo Virkki
Published: October 2020

El "bouquet" o ramillete, es decir, la polarización de los extremos de los cromosomas en un área restringida de la membrana nuclear opuesta al centrosoma y a la abertura fusomal, es un acontecimiento normal durante la meiosis en la mayoría del grupo Eukaryota. Durante la mitosis, la unión de todos los cromosomas a la membrana nuclear mediante complejos de poros nucleares persiste hasta que la membrana se rompe: el ramillete no puede ni necesita formarse. El íntimo apareamiento de los homólogos por complejos sinaptinemales requiere la separación de los cromosomas de la membrana nuclear durante la profase meiótica. Para compensar la pérdida de comunicación múltiple con el citoplasma a través de poros nucleares, los complejos de poros teloméricos se asocian directamente con el centro de actividad extranuclear, el idiosoma (= un centrosoma rodeado por el precursor de microtúbulos, los mitocondrios y el aparato Golgi). La existencia de una meiosis sin la formación del ramillete es probable cuando los homólogos están tan unidos en la membrana nuclear, que pueden aparearse sin necesidad de separarse de la membrana. El ramillete es comparable a los sistemas Prokarioto y "Mesokarioto", en los cuales los cromosomas permanecen unidos permanentemente a la envoltura celular o nuclear y/o a los equivalentes al centrosoma para fines de duplicación, funcionamiento y segregación.
Título en español.
Authors: H. E. Waterworth  , R. H. Lawson  , R. P. Kahn
Published: October 2020

Un virus latente de Dioscorea floribunda y D. composita (DLV) se purificó mediante el uso de carbón activado pulverizado y bentonita tratada con magnesio para clarificar la savia extraída de las hojas de Dioscorea. El virus produjo una sola franja en los gradientes de densidad de la sacarosa. Los antisueros producidos en un conejo alcanzaron una concentración de 1:16,000. El DLV purificado no reaccionó con los antisueros a ninguno de los 25 virus cilíndricos. Myzus persicae (Sulzer), el áfido verde del melocotón, no transmitió el DLV de plantas de Dioscorea infectadas. El 74 por ciento de las partículas midieron de 395 a 445 nm. Las plantitas de D. floribunda inoculadas no revelaron síntomas, pero el virus se observó en preparaciones por inmersión del tejido sistémicamente infectado. El DLV apareció en combinación con otro virus que era transmisible por los áfidos y que provocaba síntomas del listado verde.
Título en español.
Authors: Alex G. Alexander  , Ashok Kumar
Published: October 2020

Se estudió la distribución de la sacarosa, la clorofila, la ß-amilasa y la ATP-asa en hojas de caña de azúcar de distintos niveles, de las cuales se tomaron muestras a diferentes horas del día. A las horas 0600, 0800 y 1330 se desprendieron hojas de los niveles —2 hasta +7 y, antes del análisis, se cortaron desde la base hasta el ápice en segmentos de 30 cm. La sacarosa, de la cual se hallaron gradientes positivos basípetos en todos los niveles, alcanzó valores máximos a las 1330 horas. Para la clorofila se obtuvieron gradientes inversos (acrópetos), con grandes descensos entre las 0600 y las 0800 horas, en los segmentos que estuvieron expuestos a iluminación máxima. Entre los niveles de hojas la actividad de la ß-amilasa guardó relación inversa con la sacarosa; en las láminas individuales la relación fue positiva del ápice a la base. Ocurrieron pronunciados aumentos entre las horas 0600 y 0800 y los mismos parecían ser independientes de los cambios en la intensidad de luz y en el contenido en saracosa. Tanto la ß-amilasa como la ATP-asa estuvieron excepcionalmente activas en los niveles de hojas más jóvenes (—2), especialmente en la mitad inferior no expuesta a la luz. En hojas maduras (+1 a +7) la actividad de la ATP-asa guardó una relación constante con los parámetros de gradiente, nivel y hora. Los datos señalan hacia importantes funciones enzímicas, las cuales se discuten en términos de la hidrólisis de los poliglucósidos y del consumo de la energía usada en la transportación del azúcar.
Título en español.
Authors: A. Sotomayor-Ríos  , F. J. Juliá  , J. A. Arroyo-Aguilú
Published: October 2020

Se determinó el efecto de tres intervalos de corte (30,45 y 60 días) en el rendimiento y contenido en proteína cruda (PC), proteína digestible (PD) y minerales (calcio, Ca; fósforo, P; potasio, K y magnesio, Mg) de 10 yerbas forrajeras durante 1 año, en la Subestación de Isabela, que está localizada en la región noroeste de Puerto Rico. Las especies evaluadas incluyeron tres Brachiarias, cinco Digitarias y dos Cynodons. A los 30 días de edad, la producción de materia seca (PMS) fluctuó entre 25,859 y 19,041 libras por cuerda por año. La yerba "Transvala digitgrass" (Digitaria decumbens, PRPI 6439) obtuvo la PMS mayor y la Estrella (Cynodon nlemfuensis, PRPI 2341) presentó los contenidos más alto en PC y PD. La mayor PMS a los 45 días de edad la obtuvo la "Transvala digitgrass," la cual fue significativamente diferente (P < .05) a las nueve yerbas restantes. La PMS varió de 29,532 a 20,962 libras por acre por año. La yerba Digitaria eriantha obtuvo el contenido más alto en PC y PD. La yerba Estrella obtuvo la PMS y reveló el contenido en PC más altos a los 60 días de edad. La PMS varió de 37,504 a 30,269 libras por cuerda por año. Los contenidos promedio en Ca y Mg aumentaron a los 45 días, permaneciendo igual el de Ca a los 60 días, mientras que el de Mg disminuyó. Los contenidos promedio en P y K disminuyeron según aumentó el intervalo de corte. La habilidad de las yerbas para aumentar su producción fue alentadora, especialmente en la "Transvala digitgrass" y la Estrella. El contenido en PC y en PD fue mayor a edades tempranas, resultando en rendimientos mayores en PC. El contenido en Ca, P, K y Mg varió de acuerdo al intervalo de corte, sugiriendo la conveniencia de hacer posibles estudios de absorción y/o utilización de minerales con rumiantes.