In memory of Kelvin Kiptum: a reflection on his record-breaking marathon and the future outlook for a sub 2-h race from a drafting perspective.

BACKGROUND: Drafting is a common technique to reduce the drag experienced by elite runners on races, leading to faster finish times. The tactic has been successfully used in previous marathon world records. In the 2023 Chicago Marathon, Kenyan runner Kelvin Kiptum broke the marathon record after a 2:00:35 finish. This feat is impressive considering the lack of use of drafting, despite the availability of two pacers for the majority of the race. METHODS: In this study, the drag faced by Kiptum and his pacers during the race is calculated by means of computational fluid dynamics (CFD). The performance of each runner is evaluated from an energetic standpoint, and the analysis is extended to include more efficient drafting formations. RESULTS: Running in proper formations results in drag reductions in excess of 70% for the main runner. Our results indicate that, by properly using the advantages of drafting, Kiptum could have finished the race at a staggering 1:57:34, a full three minutes better than his own record and 215 s better than the previous world record. CONCLUSION: Proper use of drafting does indeed improve the energetic performance of a runner, allowing for lower race times and potentially helping elite runners in breaking the 2-h barrier for a marathon.

Forest fire probability under ENSO conditions in a semi-arid region: a case study in Guanajuato.

Fires can pose a threat to forest ecosystems when those ecosystems are not fire-adapted or when forest community conditions make them vulnerable to wildfires. Thus, investigating fire-prone environmental conditions is urgently needed to create action plans that preserve these ecosystems. In this sense, climate variables can determine the environmental conditions favorable for forest fires. Our study confirms that vapor pressure deficit (VPD) is an essential climate indicator for forest fires, as it is related to maximum temperatures and low humidity, representing the stress conditions for vegetation prone to fires. This study explores the extent to which ENSO phases can modulate climatic conditions that lead to high VPD over Guanajuato, a semi-arid region in central Mexico, during the dry season (March-April-May). Using fire occurrence data from MODIS (2000-2019) and Landsat 5 (1998-1999), we developed a climatic probability model for the occurrence of forest fires using VPD estimated from ERA5 reanalysis for each ENSO phase. We found that VPD and the occurrence of forest fires were higher during El Niño than under Neutral and La Niña years, with a higher risk of forest fire occurrence in Guanajuato's southern region. This study concludes that it is necessary to implement regional and local fire management plans, especially where the largest number of natural protected areas is located.

Behavioral aspects and the transmission of Monkeypox: A novel approach to determine the probability of transmission for sexually transmissible diseases.

Motivated by the 2022 worldwide Monkeypox (MPox) outbreak, a compartmental model is proposed to predict the evolution of the disease. Numerous models have been proposed for infectious diseases so far, although the number of variables makes it difficult to establish causation relations between individual factors and transmission rates. In order to evaluate the reaction of susceptible people to avoid infection during the outbreak, the rate of transmission is modeled through a unique phenomenological probabilistic approach, allowing the expression of the rate of generation of new cases in terms of two characteristics of the susceptible group: the frequency of sexual encounters and the probability of transmission given that there is a sexual encounter. Transmission rates are obtained and compared for the U.S. and several other countries. Results show reductions of up to 71% in the transmissibility parameter, which may be combined with variations in the frequency of sexual encounters (obtained through behavioral research) to determine the changes in the probability of transmission during an outbreak in a much more convenient way than current alternatives. This framework presents a valuable tool to health authorities in the understanding of future sexually transmissible disease outbreaks.

Risk factors associated to bovine brucellosis seroprevalence in the eastern region of Paraguay.

In Paraguay, whose main economic activity is cattle raising, bovine brucellosis is an endemic disease. Between May 2019 and October 2020, a national prevalence survey was implemented by the Paraguayan Veterinary Services. In the frame of that survey, a cross-sectional study was conducted in the eastern region of Paraguay to identify the risk factors that could be associated with brucellosis-positive farms and to estimate the bovine brucellosis seroprevalence and farmers' awareness about the disease. A questionnaire was administered to farmers to collect data on potential risk factors for bovine brucellosis as well as awareness on the disease. A logistic regression model was used to identify the risk factors associated with a farm brucellosis positive status. Blood samples were collected from 2551 cattle on 133 farms. The overall apparent seroprevalence was 27.8 % (95 % CI: 20.4-36.3 %) at the farm level, and 5.5 % (95 % CI: 4.7-6.5 %) at the animal level. Among 18 potential risk factors, four were associated with a farm brucellosis positive status. Farm size was associated with a higher risk of positive status in medium (20-80 cows) and large farms (>80 cows), compared with small farms (<20 cows). Barn disinfection had a protective effect on the risk of positive status. Conversely, presence of dogs and not incinerating/burying aborted material increased this risk. Even if 89 % of the farmers acknowledged being aware of the bovine brucellosis transmission to humans, only 46% of these farmers declared using protective gloves during calving or when handling abortions. The findings of this study emphasize the importance of implementing biosecurity measures and proper disposal of aborted material to control the disease. Therefore, to control the disease in Paraguay, vaccination campaigns should be accompanied by awareness campaigns addressing good farm management practices to minimize the risk of introduction and maintenance of brucellosis as well as the risk of human infection.

Analysis of cattle movement networks in Paraguay: Implications for the spread and control of infectious diseases.

Beef exports represent a substantial part of Paraguay's agricultural sector. Cattle movements involve a high risk due to the possible spread of bovine diseases that can have a significant impact on the country's economy. We analyzed cattle movements from 2014 to 2018 using the networks analysis methodology at the holding and district levels at different temporal scales. We built two types of networks to identify network characteristics that may contribute to the spread of two diseases with different epidemiological characteristics: i) a network including all cattle movements to consider the transmission of a disease of rapid spread like foot and mouth disease, and ii) a network including only cow movements to account for bovine brucellosis, a disease of slow spread that occurs mainly in adult females. Network indicators did not vary substantially among the cattle and cow only networks. The holdings/districts included in the largest strongly connected components were distributed throughout the country. Percolation analysis performed at the holding level showed that a large number of holdings should be removed to make the largest strongly connected component disappear. Higher values of the centrality indicators were found for markets than for farms, indicating that they may play an important role in the spread of an infectious disease. At the holding level (but not at the district level), the networks exhibited characteristics of small-world networks. This property may facilitate the spread of foot and mouth disease in case of re-emergence, or of bovine brucellosis in the country through cattle movements. They should be taken into account when implementing surveillance or control measures for these diseases.

Evaluation of the use of posterior tibial nerve stimulation for the treatment of fecal incontinence: preliminary results of a prospective study.

PURPOSE: Neuromodulation therapies have been used with success in patients with fecal incontinence. Intermittent percutaneous tibial nerve stimulation is a new, minimally invasive treatment option for these patients. This study was designed to evaluate the results of intermittent percutaneous tibial nerve stimulation in patients with fecal incontinence. METHODS: Sixteen patients (11 females; mean age, 59 +/- 7.9 years) with severe fecal incontinence were treated with percutaneous tibial nerve stimulation. All patients completed a defecation diary, the Wexner Fecal Continence Scale, a fecal incontinence quality-of-life questionnaire, and a visual analog scale before treatment and during each phase of the study. Endoluminal ultrasound and anorectal physiologic studies were also performed in each patient. RESULTS: Continence was improved in 10 of 16 patients after the first phase. Six patients did not continue to the second phase of treatment because of a lack of initial response. During the second phase, 7 of 16 continued to show improvement. After a six-month period without any treatment, 5 of 16 continued to have good continence. Overall, percutaneous tibial nerve stimulation significantly improved fecal continence. The Wexner score improved from a mean of 13.2 +/- 4.1 at baseline to 9 +/- 5.2 at the end of the first phase (P < 0.0005), to 8 +/- 5.7 at the end of the second phase (P = 0.001), and to 9.1 +/- 5 after 6 months without treatment (P = 0.001). Significant improvement was observed in three main domains of the fecal incontinence quality-of-life scale: coping/behavior, depression, and embarrassment. Scores on the visual analog scale improved from a mean of 4.6 +/- 1.5 at baseline to 7 +/- 2.5 at the end of the first phase (P = 0.002) and to 7.2 +/- 2.5 after 6 months without treatment (P = 0.001). CONCLUSION: Percutaneous tibial nerve stimulation is a minimally invasive and effective treatment option for patients with fecal incontinence.

Candida albicans, Staphylococcus aureus and Streptococcus mutans colonization in patients wearing dental prosthesis.

BACKGROUND: Denture stomatitis is associated to Candida albicans, different bacteria and other co-factors such as an acid pH, a carbohydrate ingestion increase, different systemic illnesses and pharmacological treatments. OBJECTIVE: The aim of this study was to determine Candida albicans, Staphylococcus aureus and Streptococcus mutans prevalence in the mucous membrane and prosthesis of patients with and without atrophic denture stomatitis and its relationship with other potential clinical co-factors. STUDY DESIGN: Saliva was collected from 105 patients (62 female and 43 male) wearing dental prosthesis in order to measure their pH. Oral samples of the mucous membrane and the internal surface of dental prosthesis were taken with sterile cotton to proceed with the microbiological study. The identification of the isolated microorganisms was performed using conventional microbiological methods. RESULTS: Diabetes and Hypertension were the most frequent systemic illnesses. High carbohydrate ingestion was observed in numerous patients. Atrophic denture stomatitis was reported in 50 patients and the pH average in saliva was of 5.2. The presence of C albicans, S. aureus and S. mutans in the mucous membrane and prosthesis was of 51.4%, 52.4% and 67.6%, respectively. C. albicans was isolated in 66.7% from the prosthesis, whereas S. aureus and S. mutans were isolated in 49.5% of those same prosthesis. C. albicans was isolated in 86% of the patients with atrophic denture stomatitis and S. aureus was isolated in a similar percentage (84% of patients). The isolation of S. mutans was less frequent, and it was observed in 16% of the oral samples of these patients. CONCLUSIONS: C. albicans, S. aureus and S. mutans frequently colonize the oral mucous of patients wearing dental prosthesis. This illness-bearing condition is more frequent in patients with denture stomatitis, even though dental prosthesis colonization is lower than in the oral mucous.

Comparación de tres métodos odontológicos para estimación de edad dental en niños hondureños / Comparison of three dental methods for estimating dental age in Honduran children

La estimación de la edad dental reviste de vital importancia en el ámbito forense por sus amplias aplicaciones en los procesos de identificación y su aplicación para estimar la edad cronológica especialmente en personas vivas, en las que no se dispone de pruebas válidas de su fecha de nacimiento. Se compararon los métodos de Dermirjian, Moorees y Nolla para estimación de la edad dental con fines de aplicación forense, para lo cual se seleccionaron 114 radiografías panorámicas de pacientes hondureños por nacimiento, de ambos sexos (57 femeninos y 57 masculinos), con edades cronológicas entre cinco y 17 años que acudieron al Servicio de Ortodoncia del Hospital Odontológico Monseñor Agustín Hombach de la Universidad Católica de Honduras en Tegucigalpa; los pacientes se seleccionaron sin agenesias dentales en la hemiarcada inferior izquierda, ni alteraciones en el desarrollo dental; sin tratamientos de apicoformación y sin extracción prematura de primeras o terceras molares. Los estadios de maduración se asignaron de acuerdo a la metodología propuesta por Demirjian, Moorrees y Nolla. La edad cronológica se obtuvo de los expedientes, se determinó la exactitud de cada método, calculando la diferencia de las medias entre la edad cronológica y la edad dental estimada por los tres métodos mediante una prueba de Wilcoxon, debido a que la muestra no presentó una distribución normal. Morrees (0.31, DE = 1.14) y Nolla (0.1, DE = 1.23) sobreestiman la edad en el sexo femenino y la subestiman en los masculinos (0.3/-0.2, DE = 1.32/1.35), mientras que el método de Demirjian subestima la edad en ambos sexos (-0.4/-0.4, DE = 1.23/1.31). Se evidenció que en la muestra estudiada no hay diferencias entre la edad cronológica y la edad dental estimada por los métodos de Demirjian, Moorees y Nolla...(AU)

Dentaduras gravitacionales inferiores: una alternativa en rebordes atróficos / Lower gravitational dentures: alternative treatment for atrophic ridges

Resumen: La estabilidad de una prótesis convencional (PC) inferior se ve afectada por una excesiva resorción mandibular; el incremento de peso de una prótesis gravitacional (PG) por su combinación metal (interno) y acrílico (externo) puede aumentarla. Objetivo: Comparar la estabilidad, desempeño masticatorio (DM), peso y percepción del paciente con reborde atrófico mandibular de PC contra PG. Material y métodos: Se solicitó el consentimiento informado en seis adultos mayores desdentados. La altura del reborde residual inferior fue medida en mm. A cada paciente se le elaboró una PC y una PG (idénticas). Se utilizó primero una y luego la otra; cada una en periodos de tiempos iguales. Al término del uso de cada prótesis se le realizó una encuesta tipo Likert y una escala visual análoga (EVA), midiendo la estabilidad clínica (escala de Woelfel), DM (tamaño medio de partícula con el alimento prueba artificial) y el peso de las prótesis (g). Se utilizó la prueba de rangos de Wilcoxon y la evaluación de correlaciones de Spearman (p = 0.05). Resultados: La prueba clínica de estabilidad resultó con diferencia significativa (p = 0.046) a favor de la PG. El análisis de las correlaciones entre variables indica que a menor movimiento mayor facilidad en el habla y la reducción del alimento. En el DM no se obtuvo diferencia estadísticamente significativa (p = 0.893). Conclusiones: A pesar de la limitación del tamaño de la muestra los resultados indican que las PG son más estables y pueden ser buena alternativa de tratamiento para pacientes con limitaciones económicas o no candidatos a cirugía.

Abstract: Stability of conventional lower prostheses (CP) is affected by excessive mandibular resorption, the greater weight of a gravitational prosthesis (GP) caused by its combination of metal (internal) and acrylic (external) can increase said stability. Objective: In patients with mandibular atrophic ridge, to compare stability, masticatory performance, weight and perception of CP in comparison with GP. Material and methods: Informed consent of six adult edentulous patients was requested. Residual lower ridge height was measured in mm. Identical CP and GP were manufactured for each patient: firstly, one was used, and then the other, each one for same periods of time. At the end of prostheses use, a Likert type survey was conducted, as well as analogous visual scale (AVS) measuring clinical stability (Woelfel scale), MP (particle mean size with artificial test foodstuff) as well as prostheses weight in grams. Wilcoxon ranking test was used as well as Spearman's correlations (p = 0.05). Results: Significant differences were found in the clinical stability test (p = 0.046) favoring GP. Correlation among variables analysis indicates that to lesser movement, greater ease for speech and food processing was found. No statistically significant difference was found in MP (p = 0.893). Conclusions: In spite of limitations imposed by sample size, results indicated that GP were more stable and could represent a suitable treatment alternative for patients who are not candidates for surgery or suffer financial limitations.

[Randomised study of the use resorbable mesh for the prevention of evisceration in colorectal surgery]. / Estudio aleatorizado sobre la utilización de mallas reabsorbibles para la prevención de la evisceración en la cirugía colorrectal.

INTRODUCTION: Evisceration is a complication that causes high morbidity and mortality, and its incidence in colorectal surgery varies between 2% and 3.5%. We evaluated the results of the use of resorbable meshes in the primary closure of laparotomies, with the purpose of preventing evisceration in colorectal surgery. PATIENTS AND METHOD: One hundred and forty three patients were included (63 females/80 males) and divided in two groups: simple closed laparotomy (Group A) (72 patients) and closed with polyglycolic mesh (Group B) (73 patients), mean age 64 years (range 24-93). We evaluated: general and previous clinical data, as well as evisceration, infection, seroma and other acute complications after the surgery. RESULTS: There were no differences between group distribution by general performances, associated pathology, clinical state and primary diagnosis. Most of Group B had programmed surgery (p = 0.045); mesh was used in 4 of 5 patients with faecal peritonitis, as expected drainage requirements were significant in Group B was needed significantly needed use drainages (Group A, 2.8%; Group B, 97.2%; p < 0.0005) and subsequent FNA after their withdrawal (p < 0.05). Overall incidence of evisceration was 3.5%, with Group A 5.6% and Group B 1.4%, with no significant differences. There were no differences in wounded infection. CONCLUSIONS: This study has not been able to demonstrate that primary closure with mesh in these patients prevents evisceration, due to small sample size, and having a high incidence of seromas. Until further studies are carried out, its use should be reserved for selected cases, as it can be used in the presence of pus or faeces.

Evaluation of the use of BioGlue in the treatment of high anal fistulas: preliminary results of a pilot study.

PURPOSE: Treatment of anal fistulas by use of adhesives is an attractive method because of its simplicity and it can be performed on an ambulatory basis. Furthermore, if the treatment is unsuccessful, adhesive use does not subsequently prevent the surgeon from utilizing alternative surgical techniques and/or products. BioGlue Surgical Adhesive is a two-component surgical adhesive composed of bovine serum albumin and glutaraldehyde. We evaluated the usefulness of BioGlue for the treatment of high transsphincter anal fistulas. METHODS: Patients diagnosed with high transsphincter anal fistulas of cryptoglandular origin, whether relapsed or not, were included in this study. A seton was placed before the injection of BioGlue into the fistula track of high transsphincter anal fistulas in patients with secondary tracts and/or purulent collections. Clinical charts, operative reports, and endoanal echography results obtained for each patient were reviewed. RESULTS: Fourteen patients (13 males; mean age, 39.9 (range, 24-66) years) with high transsphincter anal fistulas of cryptoglandular origin were recruited into the study. The average time of symptom evolution was 35.6 (range, 2-96) months. Ten of 14 cases were for relapsed fistulas. Six patients required the placement of a seton 37 (range, 32-42) days before the BioGlue injection. Patients were followed for a mean length of 13.92 (range, 3-21) months, and the fistula healed completely in only seven patients (50 percent). CONCLUSIONS: These preliminary results demonstrate that BioGlue may be useful for treating patients with high transsphincter anal fistulas. Further prospective long-term studies are needed.

Quilotórax: conceptos diagnósticos y de tratamiento / Chylothorax: diagnostic and therapeutic concepts

Se revisa la bibliografía, en relación con la fisiología del conducto torácico, la fisiopatología del quilotórax y los tratamientos médico y quirúrgico del quilotórax

La presión coloidosmótica como índice de supervivencia / Colloidosmotic pressure as a surviving rate

Se estudiaron 100 enfermos en estado crítico a los cuales se les midió la presión coloidosmótica (PCO) con el oncómetro de Weil y se determinaron las proteinas totales por electroforesis. Al calcularles la PCO con las fórmulas (F1 y F2, de Landis Pappenheimer se comprobó que la PCO se puede utilizar como índice pronóstico de superviviencia, ya que a mayor PCO aumenta ésta. La PCO medida y la calculada con la F1 pueden utilizarse indistintamente con una correlación estadística aceptable. La F2 no se correlaciona con la medida y sólo puede utilizarse con valores menores de 11.2 torr. En el enfermo grave las globulinas conservan su porcentaje de participación en la PCO como en el normal(30%).

Estudio de la personalidad de tres grupos de médicos residentes (anestesiología, cirugía general y medicina interna), a través del inventario de Douglas N. Jackson / The personality of 3 groups of residents (anesthesiology, general surgery and internal medicine, using the Douglas N. Jackson inventary

Se realizó un estudio de los rasgos de personalidad en tres grupos diferentes de médicos residentes (Anestesiología, Cirugía general y Medicina Interna). La muestra estuvo constituída por 59 médicos residentes, todos ellos en el último año de entrenamiento en su especialidad (34 de anestesiología, 14 de cirugía general y 11 de medicina interna). Se les aplicó el cuestionario del Inventario de la Personalidad de Douglas N. Jackson (PRF), con un total de 17,700 respuestas. Se observó similitud en seis de las necesidades (con promedios que sobrepasaron la línea media de diez). Esta similitud puede deberse a que pertenecen a un grupo médico básico, sin embargo también se observaron algunas características diferenciales de cada grupo. Este estudio sugiere que la selección de la especialidad está ado por la personalidad del individuo, misma que marca diferencias significativas para el grupo de cirugía general en cuatro comparaciones. Este análisis estuvo caracterizado como sigue: 1§ Anestesiología: Evasión. 2§ Medicina Interna: con independencia y 3§ Cirugía general: necesidad de reconocimiento social, agresividad y resistencia