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1.
Food Nutr Bull ; 45(1_suppl): S10-S15, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38987881

ABSTRACT

BACKGROUND: Little attention has been given to prenatal cobalamin insufficiency in settings where dietary cobalamin intake is presumed adequate, such as populations with habitual intake of foods from animal sources. RESULTS: However, low cobalamin status in women of fertile age has been reported in Europe, United States, and Canada. In India, where cobalamin deficiency is highly prevalent, it has been associated with an increased risk of miscarriage, intrauterine growth retardation, as well as insulin resistance and lower neurodevelopment scores in the offspring. Low cobalamin status in pregnancy has been associated with similar outcomes as those reported in the Indian studies although the evidence is scant and conflicting. CONCLUSIONS: Consideration should be given to maternal cobalamin status in the context of prevention of adverse pregnancy outcomes as well as cobalamin insufficiency both in the mother and the offspring during lactation. Further attention is now justified with the increasing tendency toward plant-based diets. Reference intervals for cobalamin status during each trimester of pregnancy are needed and further investigation of the long-term conse-quences of low cobalamin status during pregnancy for health and development in the offspring is warranted.


Plain language titleInadequate cobalamin status during critical periods of growth and development can have negative consequences on maternal and childhood health.


Subject(s)
Nutritional Status , Pregnancy Outcome , Vitamin B 12 Deficiency , Vitamin B 12 , Humans , Pregnancy , Female , Vitamin B 12/administration & dosage , Vitamin B 12/blood , Vitamin B 12 Deficiency/epidemiology , Pregnancy Complications , India/epidemiology , Maternal Nutritional Physiological Phenomena , Fetal Growth Retardation
2.
VideoGIE ; 9(5): 226-228, 2024 May.
Article in English | MEDLINE | ID: mdl-38766397

ABSTRACT

Video 1Peroral endoscopic septotomy for Zenker's diverticulum with additional cut of mucosal flap: step by step.

3.
Rev Gastroenterol Peru ; 44(1): 63-66, 2024.
Article in English | MEDLINE | ID: mdl-38734913

ABSTRACT

After bariatric surgery one of the most common complications is dysphagia. The etiology of this disease has not been fully elucidated but it is known that it may be due to structural changes due to surgery. This case describes a 65-year-old female with early and severe onset of dysphagia following laparoscopic sleeve gastrectomy. The patient's final diagnosis was postobesity surgery esophageal dysfunction and laparoscopic proximal gastrectomy with esophagojejunal Roux-en-Y anastomosis was performed. Physicians should be aware of this condition in order to offer early diagnosis and treatment.


Subject(s)
Gastrectomy , Laparoscopy , Humans , Female , Aged , Laparoscopy/adverse effects , Gastrectomy/adverse effects , Deglutition Disorders/etiology , Deglutition Disorders/diagnosis , Obesity, Morbid/surgery , Obesity, Morbid/complications , Postoperative Complications/etiology , Postoperative Complications/diagnosis , Severity of Illness Index
4.
Open Forum Infect Dis ; 11(2): ofad690, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38370296

ABSTRACT

Background: Fungal meningitis can be associated with epidural anesthesia procedures. Fusariosis is a rare infection typically affecting immunocompromised patients and rarely causes meningitis. During 2022-2023, public health officials responded to a large outbreak of Fusarium solani meningitis associated with epidural anesthesia in Durango, Mexico. Methods: The public health response and epidemiological and clinical features of patients affected by this outbreak were described. Coordinated actions were addressed to identify the etiological agent, determine its drug susceptibility, develop diagnostic tests, and implement clinical and epidemiological protocols. Retrospective analyses of clinical variables and outcomes were performed to determine association with better patient survival. Results: A total of 1801 persons exposed to epidural anesthesia were identified, of whom 80 developed meningitis. Fusarium solani was found in 3 brain biopsies and showed susceptibility to voriconazole and amphotericin B. After F solani polymerase chain reaction (PCR) implementation, 57 patients with meningitis were PCR-screened, and 31 (38.8%) had a positive result. Most patients were female (95%), and cesarean section was the most common surgical procedure (76.3%). The case fatality rate was 51.3% (41 patients) and the median hospitalization duration was 39.5 days (interquartile range, 18-86 days). Seventy-one patients (88.8%) received voriconazole/amphotericin B and 64 subjects (80%) additionally received steroids. Cox regression analysis showed an increased lethality risk in patients who received antifungal treatment after 5 days (hazard ratio, 2.1 [95% confidence interval, 1.01-4.48], P < .05). Conclusions: The F solani meningitis outbreak in Durango was an unprecedented medical challenge. Timely treatment and effective healthcare management were associated with better survival outcomes.

5.
Am J Med ; 137(6): 545-551.e6, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38401676

ABSTRACT

BACKGROUND: Ultrasound can overcome barriers to visualizing the internal jugular vein, allowing hepato-jugular reflux and jugular venous pressure measurement. We aimed to determine operating characteristics of the ultrasound hepato-jugular reflux and ultrasound jugular venous pressure predicting right atrial and pulmonary capillary occlusion pressures. METHODS: In a prospective observational cohort at three US academic hospitals the hepato-jugular reflux and jugular venous pressure were measured with ultrasound before right heart catheterization. Receiver operating curves, likelihood ratios, and regression models were utilized to compare the ultrasound hepato-jugular reflux and ultrasound jugular venous pressure to the right atrial and pulmonary capillary occlusion pressures. RESULTS: In 99 adults undergoing right heart catheterization, an ultrasound hepato-jugular reflux had a negative likelihood ratio of 0.4 if 0 cm and a positive likelihood ratio of 4.3 if ≥ 1.5 cm for predicting a pulmonary capillary occlusion pressure ≥ 15 mmHg. Regression modeling predicting pulmonary capillary occlusion pressure was not only improved by including the ultrasound hepato-jugular reflux (P < .001), it was the more impactful predictor compared with the ultrasound jugular venous pressure (adjusted odds ratio 2.6 vs 1.2). The ultrasound hepato-jugular reflux showed substantial agreement (kappa 0.76; 95% confidence interval, 0.30-1.21), with poor agreement for the ultrasound jugular venous pressure (kappa 0.11; 95% confidence interval, -0.37-0.58). CONCLUSION: In patients undergoing right heart catheterization, the ultrasound hepato-jugular reflux is reproducible, has modest impact on the probability of a normal pulmonary capillary occlusion pressure when 0 cm, and more substantial impact on the probability of an elevated pulmonary capillary occlusion pressure when ≥ 1.5 cm.


Subject(s)
Cardiac Catheterization , Jugular Veins , Ultrasonography , Humans , Jugular Veins/diagnostic imaging , Male , Female , Cardiac Catheterization/methods , Middle Aged , Prospective Studies , Ultrasonography/methods , Aged , Central Venous Pressure , Adult
6.
Rev. gastroenterol. Perú ; 44(1): 63-66, ene.-mar. 2024. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1560050

ABSTRACT

ABSTRACT After bariatric surgery one of the most common complications is dysphagia. The etiology of this disease has not been fully elucidated but it is known that it may be due to structural changes due to surgery. This case describes a 65-year-old female with early and severe onset of dysphagia following laparoscopic sleeve gastrectomy. The patient's final diagnosis was postobesity surgery esophageal dysfunction and laparoscopic proximal gastrectomy with esophagojejunal Roux-en-Y anastomosis was performed. Physicians should be aware of this condition in order to offer early diagnosis and treatment.


RESUMEN Después de una cirugía bariátrica una de las complicaciones más comunes es la disfagia. La etiología de esta enfermedad no ha sido completamente dilucidada, pero se sabe que puede deberse a cambios estructurales debidos a la cirugía. En este reporte se describe el caso de una mujer de 65 años con disfagia severa de aparición temprana después de una en manga gástrica laparoscópica. El diagnóstico final del paciente fue de una disfunción esofágica posterior a una cirugía de obesidad y se planteó como manejo una gastrectomía proximal laparoscópica con anastomosis esofagoyeyunal en Y de Roux. Hay que tener en cuenta las complicaciones a corto y largo plazo que se pueden presentar luego de cirugías de obesidad para poder realizar un diagnóstico temprano y poder ofrecer un tratamiento adecuado.

7.
Rev. esp. patol ; 56(4): 275-278, Oct-Dic, 2023. ilus
Article in English | IBECS | ID: ibc-226962

ABSTRACT

Synovial sarcoma is a soft tissue tumor of uncertain origin. Generally, it is a monophasic spindle cell neoplasm that can have glandular-like structures. Ossification and presence of calcification is a rare phenomenon with only a few reported cases. We present the case of a young male with a synovial sarcoma of the right foot. Histology revealed prominent deposits of tumoral osteoid and coarse calcifications. The diagnosis was confirmed by the expression of SS18 by immunohistochemistry and the demonstration of the rearrangement of the SS18 gene by fluorescent in situ hybridization. We reviewed the literature for synovial sarcoma with prominent ossification or calcification, and to the best of our knowledge, this is the first case with expression of SS18 by immunohistochemistry. The main differential diagnoses are osteosarcoma (both primary of bone and extraosseous) and sclerosing epithelioid fibrosarcoma.(AU)


El sarcoma sinovial (SS) es un tumor de partes blandas de origen incierto. Generalmente es una neoplasia monofásica de células fusiformes que puede tener estructuras de tipo glandular. La osificación y la presencia de calcificaciones es un fenómeno raro, con pocos casos reportados. A continuación presentamos el caso de un hombre joven con un sarcoma sinovial del pie derecho que en la histología mostró depósitos de osteoide tumoral y calcificaciones gruesas. El diagnóstico fue confirmado por la expresión de SS18 por inmunohistoquímica y la demostración del reordenamiento del gen SS18 por hibridación in situ fluorescente. Revisamos la literatura referente a sarcoma sinovial con osificación o calcificación prominente, y este es el primer caso con expresión de SS18 por inmunohistoquímica. Los principales diagnósticos diferenciales son con osteosarcoma (tanto primario de hueso como extraóseo) y fibrosarcoma epitelioide esclerosante (sclerosing epithelioid fibrosarcoma [SEF]).(AU)


Subject(s)
Humans , Male , Adult , Sarcoma, Synovial , Osteogenesis , Immunohistochemistry , In Situ Hybridization, Fluorescence , Fibrosarcoma , Foot/pathology , Inpatients , Physical Examination , Magnetic Resonance Spectroscopy
8.
Rev Esp Enferm Dig ; 2023 Oct 26.
Article in English | MEDLINE | ID: mdl-37882161

ABSTRACT

We present the case of a 47-year-old man with a history of refractory multiple myeloma who was referred to our hospital for the presence of a colonic lesion suspected of having signs of deep submucosal invasion. After a surgical resection, the histological study revealed that it was a case of malakoplakia that had developed at the base of a tubular adenoma.

9.
Rev Esp Patol ; 56(4): 275-278, 2023.
Article in English | MEDLINE | ID: mdl-37879825

ABSTRACT

Synovial sarcoma is a soft tissue tumor of uncertain origin. Generally, it is a monophasic spindle cell neoplasm that can have glandular-like structures. Ossification and presence of calcification is a rare phenomenon with only a few reported cases. We present the case of a young male with a synovial sarcoma of the right foot. Histology revealed prominent deposits of tumoral osteoid and coarse calcifications. The diagnosis was confirmed by the expression of SS18 by immunohistochemistry and the demonstration of the rearrangement of the SS18 gene by fluorescent in situ hybridization. We reviewed the literature for synovial sarcoma with prominent ossification or calcification, and to the best of our knowledge, this is the first case with expression of SS18 by immunohistochemistry. The main differential diagnoses are osteosarcoma (both primary of bone and extraosseous) and sclerosing epithelioid fibrosarcoma.


Subject(s)
Calcinosis , Sarcoma, Synovial , Humans , Male , In Situ Hybridization, Fluorescence , Sarcoma, Synovial/genetics , Sarcoma, Synovial/pathology , Osteogenesis , Biomarkers, Tumor/genetics , Calcinosis/genetics
10.
Sci Data ; 10(1): 474, 2023 07 20.
Article in English | MEDLINE | ID: mdl-37474536

ABSTRACT

This article reports temperature-dependent elastic properties (Young's modulus, shear modulus) of three alloys measured by the dynamic resonance method. The alloys Ti-6Al-4V, Inconel IN718, and AISI 316 L were each investigated in a variant produced by an additive manufacturing processing route and by a conventional manufacturing processing route. The datasets include information on processing routes and parameters, heat treatments, grain size, specimen dimensions, and weight, as well as Young's and shear modulus along with their measurement uncertainty. The process routes and methods are described in detail. The datasets were generated in an accredited testing lab, audited as BAM reference data, and are hosted in the open data repository Zenodo. Possible data usages include the verification of the correctness of the test setup via Young's modulus comparison in low-cycle fatigue (LCF) or thermo-mechanical fatigue (TMF) testing campaigns, the design auf VHCF specimens and the use as input data for simulation purposes.

12.
Ann Gastroenterol ; 36(2): 167-177, 2023.
Article in English | MEDLINE | ID: mdl-36864932

ABSTRACT

Background: Endoscopic submucosal dissection (ESD) is now considered the standard treatment for early gastric cancer (EGC). However, the widespread adoption of ESD in western countries has been slow. We performed a systematic review to evaluate short-term outcomes of ESD for EGC in non-Asian countries. Methods: We searched 3 electronic databases from inception until October 26, 2022. Primary outcomes were en bloc, R0 and curative resections rate by region. Secondary outcomes were overall complications, bleeding, and perforation rate by region. The proportion of each outcome, with the 95% confidence interval (CI), was pooled using a random-effects model with the Freeman-Tukey double arcsine transformation. Results: Twenty-seven studies from Europe (n=14), South America (n=11) and North America (n=2) were included, involving 1875 gastric lesions. Overall, en bloc, R0, and curative resection rates were achieved in 96% (95%CI 94-98%), 85% (95%CI 81-89%), and 77% (95%CI 73-81%) of cases, respectively. Considering only information from lesions with adenocarcinoma, the overall curative resection was 75% (95CI 70-80%). Bleeding and perforation were observed in 5% (95%CI 4-7%) and 2% (95%CI 1-4%) of cases, respectively. Conclusion: Our results suggest that short-term outcomes of ESD for the treatment of EGC are acceptable in non-Asian countries.

13.
Rev. gastroenterol. Peru ; 42(4)oct. 2022.
Article in English | LILACS-Express | LILACS | ID: biblio-1423949

ABSTRACT

Barrett's esophagus (BE) is a known precursor of dysplasia and adenocarcinoma. Endoscopic resection and surgery are the techniques used to treat these kinds of lesions. However, endoscopic resection is considered the first choice for the management of superficial lesions. Dysplasia in BE most commonly appears like a flat lesion but here we describe an unusual case of dysplasia and superficial adenocarcinoma looking like an extensive polypoid lesion.


El esófago de Barrett (EB) es un precursor conocido de displasia y adenocarcinoma. La resección endoscópica y la cirugía son las técnicas utilizadas para tratar este tipo de lesiones. Sin embargo, la resección endoscópica se considera la primera opción para el manejo de las lesiones superficiales. La displasia en EB aparece más comúnmente como una lesión plana, pero aquí describimos un caso inusual de displasia y adenocarcinoma superficial que parece una lesión polipoide extensa.

14.
PLoS One ; 17(3): e0265529, 2022.
Article in English | MEDLINE | ID: mdl-35358238

ABSTRACT

PURPOSE: The COVID-19 pandemic has spread worldwide, and almost 396 million people have been infected around the globe. Latin American countries have been deeply affected, and there is a lack of data in this regard. This study aims to identify the clinical characteristics, in-hospital outcomes, and factors associated with ICU admission due to COVID-19. Furthermore, to describe the functional status of patients at hospital discharge after the acute episode of COVID-19. MATERIAL AND METHODS: This was a prospective, multicenter, multinational observational cohort study of subjects admitted to 22 hospitals within Latin America. Data were collected prospectively. Descriptive statistics were used to characterize patients, and multivariate regression was carried out to identify factors associated with severe COVID-19. RESULTS: A total of 3008 patients were included in the study. A total of 64.3% of patients had severe COVID-19 and were admitted to the ICU. Patients admitted to the ICU had a higher mean (SD) 4C score (10 [3] vs. 7 [3)], p<0.001). The risk factors independently associated with progression to ICU admission were age, shortness of breath, and obesity. In-hospital mortality was 24.1%, whereas the ICU mortality rate was 35.1%. Most patients had equal self-care ability at discharge 43.8%; however, ICU patients had worse self-care ability at hospital discharge (25.7% [497/1934] vs. 3.7% [40/1074], p<0.001). CONCLUSIONS: This study confirms that patients with SARS CoV-2 in the Latin American population had a lower mortality rate than previously reported. Systemic complications are frequent in patients admitted to the ICU due to COVID-19, as previously described in high-income countries.


Subject(s)
COVID-19 , COVID-19/epidemiology , Cohort Studies , Hospital Mortality , Hospitals , Humans , Intensive Care Units , Latin America/epidemiology , Pandemics , Prospective Studies
15.
Environ Sci Technol ; 56(4): 2300-2311, 2022 02 15.
Article in English | MEDLINE | ID: mdl-35103467

ABSTRACT

Acute environmental perturbations are reported to induce deterministic microbial community assembly, while it is hypothesized that chronic perturbations promote development of alternative stable states. Such acute or chronic perturbations strongly impact on the pre-adaptation capacity to the perturbation. To determine the importance of the level of microbial pre-adaptation and the community assembly processes following acute or chronic perturbations in the context of hydrocarbon contamination, a model system of pristine and polluted (hydrocarbon-contaminated) sediments was incubated in the absence or presence (discrete or repeated) of hydrocarbon amendment. The community structure of the pristine sediments changed significantly following acute perturbation, with selection of different phylotypes not initially detectable. Conversely, historically polluted sediments maintained the initial community structure, and the historical legacy effect of chronic pollution likely facilitated community stability. An alternative stable state was also reached in the pristine sediments following chronic perturbation, further demonstrating the existence of a legacy effect. Finally, ecosystem functional resilience was demonstrated through occurrence of hydrocarbon degradation by different communities in the tested sites, but the legacy effect of perturbation also strongly influenced the biotic response. This study therefore demonstrates the importance of perturbation chronicity on microbial community assembly processes and reveals ecosystem functional resilience following environmental perturbation.


Subject(s)
Ecosystem , Microbiota , Environmental Pollution , Hydrocarbons/metabolism
16.
Int J Obes (Lond) ; 46(3): 661-668, 2022 03.
Article in English | MEDLINE | ID: mdl-34974543

ABSTRACT

BACKGROUND: Patients with obesity have an increased risk for adverse COVID-19 outcomes. Body mass index (BMI) does not acknowledge the health burden associated this disease. The performance of the Edmonton Obesity Staging System (EOSS), a clinical classification tool that assesses obesity-related comorbidity, is compared with BMI, with respect to adverse COVID-19 outcomes. METHODS: 1071 patients were evaluated in 11 COVID-19 hospitals in Mexico. Patients were classified into EOSS stages. Adjusted risk factors for COVID-19 outcomes were calculated and survival analysis for mechanical ventilation and death was carried out according to EOSS stage and BMI category. RESULTS: The risk for intubation was higher in patients with EOSS stages 2 and 4 (HR 1.42, 95% CI 1.02-1.97 and 2.78, 95% CI 1.83-4.24), and in patients with BMI classes II and III (HR 1.71, 95% CI 1.06-2.74, and 2.62, 95% CI 1.65-4.17). Mortality rates were significantly lower in patients with EOSS stages 0 and 1 (HR 0.62, 95% CI 0.42-0.92) and higher in patients with BMI class III (HR 1.58, 95% CI 1.03-2.42). In patients with a BMI ≥ 25 kg/m2, the risk for intubation increased with progressive EOSS stages. Only individuals in BMI class III showed an increased risk for intubation (HR 2.24, 95% CI 1.50-3.34). Mortality risk was increased in EOSS stages 2 and 4 compared to EOSS 0 and 1, and in patients with BMI class II and III, compared to patients with overweight. CONCLUSIONS: EOSS was associated with adverse COVID-19 outcomes, and it distinguished risks beyond BMI. Patients with overweight and obesity in EOSS stages 0 and 1 had a lower risk than patients with normal weight. BMI does not adequately reflect adipose tissue-associated disease, it is not ideal for guiding chronic-disease management.


Subject(s)
COVID-19 , Obesity , Adult , Aged , COVID-19/complications , COVID-19/epidemiology , COVID-19/mortality , Comorbidity , Female , Hospitalization , Humans , Male , Middle Aged , Obesity/complications , Obesity/epidemiology , Obesity/physiopathology , Retrospective Studies , Severity of Illness Index , Treatment Outcome
17.
Clin Endosc ; 55(2): 248-255, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34763382

ABSTRACT

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) is the preferred technique for treating early gastric cancer (EGC). However, very few studies have been conducted in South America. This study aimed to assess the efficacy and safety of ESD for EGC. METHODS: We analyzed data from a prospective cohort from 2013 to 2020. A total of 152 superficial gastric neoplasms that fulfilled the absolute or expanded criteria for ESD were included. Outcomes were en bloc, R0, and curative resection rates, incidence of adverse events, and length of procedure. RESULTS: The age of the enrolled patients was 68.4±11.3 years. The number of included patients based on the absolute and expanded indications was 150 and 2, respectively. En bloc, R0, and curative resections were achieved in 98.0%, 96.1%, and 89.5% of the cases, respectively. Bleeding and perforation were reported in 5.9% and 6.6% of the cases, respectively. Histopathological examination revealed lowgrade dysplasia, high-grade dysplasia, well-differentiated adenocarcinoma, and poorly differentiated adenocarcinoma in 13, 20, 117, and 2 cases, respectively. CONCLUSION: Our study shows that ESD performed by properly trained endoscopists in reference centers is safe and effective, with comparable therapeutic outcomes to those reported in the Eastern series.

18.
Rev Gastroenterol Peru ; 42(4): 248-250, 2022.
Article in English | MEDLINE | ID: mdl-36746465

ABSTRACT

Barrett's esophagus (BE) is a known precursor of dysplasia and adenocarcinoma. Endoscopic resection and surgery are the techniques used to treat these kinds of lesions. However, endoscopic resection is considered the first choice for the management of superficial lesions. Dysplasia in BE most commonly appears like a flat lesion but here we describe an unusual case of dysplasia and superficial adenocarcinoma looking like an extensive polypoid lesion.


Subject(s)
Adenocarcinoma , Barrett Esophagus , Esophageal Neoplasms , Polyps , Humans , Barrett Esophagus/complications , Barrett Esophagus/diagnosis , Barrett Esophagus/pathology , Esophageal Neoplasms/diagnosis , Esophageal Neoplasms/surgery , Esophagoscopy/methods , Adenocarcinoma/diagnosis , Adenocarcinoma/surgery , Adenocarcinoma/pathology , Hyperplasia , Polyps/pathology
19.
Evodevo ; 12(1): 10, 2021 Sep 27.
Article in English | MEDLINE | ID: mdl-34579780

ABSTRACT

The Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195-269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community.

20.
Pak J Biol Sci ; 24(4): 468-476, 2021 Jan.
Article in English | MEDLINE | ID: mdl-34486306

ABSTRACT

<b>Background and Objective:</b> Forage production in the tropics is generally asymmetrically distributed. Hence the need to use more complex models, especially when multiple comparisons are made and there are very large deviations from normality. The objective of this research is to fit a Generalized Additive Model for Location, Scale and Shape (GAMLSS) model on accumulated dry matter data from <i>Brachiaria brizantha</i> using a model selection algorithm. <b>Materials and Methods:</b> A Box-Cox Power Exponential (BCPE) distribution was adjusted on the dry matter from <i>Brachiaria brizantha</i> data implementing GAMLSS in R (programming language). The accumulated dry matter data for <i>B. brizantha</i> were obtained from a study carried out on a farm in the state of Portuguesa, Venezuela. The explanatory covariate x was the interval between cuts (21, 28, 35 and 42 days). <b>Results:</b> The dependent variable (dry matter) exhibited both skewness and kurtosis. GAMLSS allowed flexible modeling of both the distribution of the dry matter yield from <i>B. brizantha</i> and the dependence of all the parameters of the distribution on intervals between cuttings. For the dry matter yield from <i>B. brizantha</i>, which exhibited skewness and leptokurtosis, the BCPE distribution, provided the best fit. <b>Conclusion:</b> The interval between cuttings showed an effect that is reflected in the average yield of dry matter from <i>B. brizantha</i>. The interval between cuts affected the skewness and the kurtosis of the distribution.


Subject(s)
Algorithms , Brachiaria/growth & development , Geographic Mapping , Agriculture/methods , Humans , Venezuela
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