Aplicación teórica del método Holt-Winters al problema de Credit Scoring

El incremento de las instituciones de microfinanzas (imf) en México ha agudizado la competencia entre estas instituciones para aumentar su participación de mercado. No obstante las imf deben de valorar de manera adecuada el otorgamiento de créditos a sus clientes potenciales. Que los posibles clientes puedan pagar o no sus créditos depende directamente de los flujos de efectivo que generen por sus operaciones. En este trabajo se hace una revisión de la literatura de los trabajos más relevantes sobre los diferentes modelos de credit scoring y se propone una metodología teórica para analizar el riesgo de crédito en la concesión de microcréditos a partir de los flujos de efectivo esperados haciendo énfasis en la estacionalidad que dichos flujos presentan. Para ello se emplea el método Holt-Winters de pronóstico no lineal, con el fin de predecir el riesgo de que un cliente pague un préstamo (credit scoring)

Supply Chain and Economic Viability of Vanilla planifolia Andrew Production: A Case Study

Objective: Characterize the supply chain of Planifolia Andrew vanilla in order to detect improvement areas and also determine the economic viability for its production. Design/methodology/approach: Information about supply chain was collected through semi-structured interviews into a vanilla company. The Value Stream Mapping technique was used to characterize the supply chain. Additional databases were consulted in order to get information about vanilla production and commercialization. The economic viability of vanilla production was analyzed by IRR. Results: The case of study has 5 stages in its supply chain. The cash flows IRR of the traditional and technified production systems were positive, although the IRR of the traditional system was higher despite to have a lower production volume. Limitations on study/implications: We observed that vanilla requires between 3 and 4 years for its first harvest, regardless the production system, this implies that despite the IRR of both systems are positive there are negative cash flows in the first two years. Findings/conclusions: The critical stage in the supply chain in the studied company was production. Cash flows of the technified system were higher than the traditional system. However, the IRR of the technified system is lower, due to the investment in shadow mesh is not offset by the discounted cash flows that could be obtained.  Objectives: To characterize the supply chain of vanilla (Vanilla planifolia Andrew) inorder to detect areas which could be improved and to determine the economic viabilityof its production.Design/Methodology/Approach: The information was compiled through semi-structured interviews in a vanilla company. The Value Stream Mapping technique wasused to describe the supply chain. Additional databases were consulted in order toobtain information on the production and commercialization of vanilla. The economicviability of vanilla production was analyzed with IRR.Results: This case study had five phases in its supply chain. The IRR of cash flow inthe traditional and technological production systems were positive, although the IRR ofthe traditional system was greater even though it had lower production volumes.Study Limitations/Implications: It was observed that vanilla requires between 3 and 4years for its first harvest, independently of the production system, traditional ortechnological, which means that there are negative cash flow numbers during the firsttwo years in both systems, despite a positive IRR.Findings/Conclusions: The critical stage in the supply chain of the company studiedwas the production. The cash flow for the technological system was superior whencompared to the traditional system. However, the IRR for the technological system waslower, since the investment in shade cloth was not compensated by the discountedcash flows that could otherwise be obtained

Anatomical Variants of Anterior Cerebral Arterial Circle: A Study by Multidetector Computerized 3D Tomographic Angiography

SUMMARY: One of the most common causes of stroke is rupture of aneurysms whose approach requires knowledge of anatomical variants. The aim of this study was to determine the prevalence of anatomical variants of the anterior cerebral artery (ACA) and the anterior communicating artery (AComA) by 3D computed tomography angiography (3D CTA) in Mexican individuals. A retrospective, observational, cross-sectional descriptive study of 283 patients, independent of sex or age, in which morphometric measurements of cerebral vessels were evaluated using contrasted 3D CTA from a period of two years was performed. We found at least one "atypical" variant in a third of the study population (33.93 %). The most common "atypical" variant was the absence of the AComA (14.1 %). A significant association between the hypoplastic variant of the right A1 segment and hypoplasia of the left A1 and the right A2 was found, while hypoplasia of the left A1 was associated with hypoplasia of the right A2. There is a difference in the prevalence of anatomical variants of the ACA-AComA complex in Mexican population in relation to other populations. The typical variant is the most prevalent form in the study population. However, the presence of atypical variants represents an important number that should be taken into account in clinical and surgical procedures. KEY WORDS: Anterior cerebral artery; Anatomical variant; Anterior communicating artery; Cerebral arterial circle; Subarachnoid hemorrhage; Cerebral endovascular surgery

Enhancing appropriate statin therapy in Type 2 Diabetic patients aged between 40-75 years at Graduate Medical Education (GME) Internal Medicine clinic

Background: The prevalence of type 2 diabetes mellitus (T2DM) is significantly higher in Rio Grande Valley than the rest of the United States. T2DM patients have an elevated risk of Atherosclerotic cardiovascular disease (ASCVD), and clinical trials have demonstrated the beneficial effects of statin therapy on ASCVD. A quality-improvement project was implemented in the GME Internal Medicine (IM) Clinic at Doctors Hospital at Renaissance to improve statin therapy appropriateness. Methods: T2DM patients aged 40-75 were selected from the GME IM Clinic visits from July 2021 to October 2021 for baseline data and from January 2022 to April 2022 after implementing our interventions, which included education of the new practice guidelines of statin therapy in T2DM to the internal medicine residents, as well as development of a clinical decision support tool designed to assess the indication and intensity of statin therapy. Exclusion criteria included patients without T2DM, ages above 75/below 40 years of age, and missing information for ASCVD risk stratification. Statin appropriateness was determined according to the American Diabetes Association standards in diabetes management. Results: The number of patients in the four months after the exclusions pre-intervention and post-intervention were 153 and 207, respectively. Overall, 71.9% (n=110) of the patients pre-intervention were receiving an appropriate statin therapy; the number increased to 80% (n=166) post-intervention (p = 0.003), considered statistically significant using t-test analysis. Of the total patients (N=43) with inappropriate statin therapy, 37% (n=16) had inadequate dose, and 63% (n=27) were not receiving any statin in the pre-intervention cohort. This percentage of inadequate statin dose and no statin therapy decreased to 65% (n=27) and 35% (n=14), respectively post-intervention. Conclusion: Appropriate statin therapy has been shown to reduce all-cause mortality by 19% in T2DM. Appropriateness of statin therapy was increased by 10%, and more than 50% reduction of patients without receiving any statin therapy, after our intervention. Effective implementation of new guidelines regarding risk stratification and prevention of ASCVD in T2DM age 40-75 years of age may be challenging. Barriers such as physicians\u27 adoption and knowledge regarding new guidelines can be overcome with appropriate tools and education, such as those implemented in our project

4-1BBL as a Mediator of Cross-Talk between Innate, Adaptive, and Regulatory Immunity against Cancer

The ability of tumor cells to evade the immune system is one of the main challenges we confront in the fight against cancer. Multiple strategies have been developed to counteract this situation, including the use of immunostimulant molecules that play a key role in the anti-tumor immune response. Such a response needs to be tumor-specific to cause as little damage as possible to healthy cells and also to track and eliminate disseminated tumor cells. Therefore, the combination of immunostimulant molecules and tumor-associated antigens has been implemented as an antitumor therapy strategy to eliminate the main obstacles confronted in conventional therapies. The immunostimulant 4-1BBL belongs to the tumor necrosis factor (TNF) family and it has been widely reported as the most effective member for activating lymphocytes. Hence, we will review the molecular, pre-clinical, and clinical applications in conjunction with tumor-associated antigens in antitumor immunotherapy, as well as the main molecular pathways involved in this association

Neurovascular Structures at Risk During Anterolateral and Medial Arthroscopic Approaches of the Hip

To describe the safety areas for placement of 5 anterolateral portals (anterior, anterior lateral, posterior lateral, proximal anterior medial and distal anterior medial portals) and 3 recently described medial portals (anterior medial, posterior medial and distal posterior medial portals) to provide topographical description of the safety of each. A descriptive, observational and crosssectional study in which femoral triangle dissection was performed in 12 hips. 5 lateral portals and the 3 medial portals were placed. Clinically relevant neurovascular structures associated with each portal, were identified measured and documented. The lateral portal with the highest risk of injury to a nearby neurovascular structure was the anterior portal, the most adjacent to the femoral cutaneous nerve, 1.42 cm (±0.85) lateral to the portal. In the medial portals, the anterior medial portal has the narrowest margin in relation to the femoral artery, 2.14 cm (±0.35) lateral to the portal and medial to the obturator nerve by 0.87 cm (±0.62). The lateral portals have a higher safety margin; the portal with the most proximity to a neurovascular structure is the anterior portal, associated laterally with the femoral cutaneous nerve, presenting a higher risk of injury. Medial portals have a higher risk of injuring the femoral neurovascular bundle as well as the obturator nerve

Histomorphometric and Immunohistochemical Study of Early Adaptative Response of the Vascular Wall in a Termino-Terminal Microsurgical Model of Femoral Vessels in Wistar Rat

SUMMARY: When a vein segment is grafted into arterial circulation, biomechanical forces stimulate modification of its structure. This morphological adaptive response is progressive during a medium or long term and occludes the vessel lumen, leading to a graft failure. The objective of this study was to characterize the early morphological response of the vascular wall in a terminal-terminal vascular vein graft model in Wistar rats. A segment of the femoral vein was placed in the femoral circulation. An end to end microsurgical graft anastomosis technique was implemented and standardized in twenty rats. The samples were processed with histological technique to analyze the overall structure with hematoxylin and eosin, the composition of the vessel wall with Masson trichrome technique, the proliferating and smooth muscle cells were detected with immunohistochemistry (anti-PCNA, anti-actin and anti CD68) and the induction of apoptosis with TUNEL technique. The times periods studied were 1, 3 and 5 days postoperative. There is progressive increase of cell proliferation and intensity of the density detected by PCNA with its peak at postoperative day 3. Apoptosis was not evident in any of the postoperative days. Smooth muscle had no significant change in any of the time periods studied. Macrophage and leukocyte migration was evident since the first postoperative day with infiltration into the media by the 5th day. This study characterizes the morphological aspects in the early arterialization of the vascular wall in a vein graft process. These results contribute to a better understanding of the morphopathological mechanism involved in vein graft failure. KEY WORDS: Hyperplasia; Morphology; Microsurgical model; Vascular adaptive changes; Venous graft

Morphological Analysis of Bronchial Arteries and Variants with Computed Tomography Angiography

The aim of our study was to determine the prevalence of anatomical variants of bronchial arteries using computed tomographic angiography in a population of northeastern Mexico. An observational, transversal, descriptive, comparative, retrospective study was performed using 139 imaging studies of Mexican patients in which we evaluated the following parameters from the left and right bronchial arteries: artery origin, branching pattern, arterial ostium, vertebral level of origin, diameter, and mediastinal trajectory. The anatomies of the bronchial arteries were similar in both genders, except distribution for vertebral origin level

Morphological Analysis of Major Segments of Coronary Artery Occlusion: Importance in Myocardial Revascularization Surgery

Revascularization surgery should ensure morphological similarity between the coronary artery and the graft. This is an important factor for its duration and permeability. The aim of this study was to analyze the morphological characteristics and morphometrics of the coronary artery segments with greater occlusion. This was an observational, cross-sectional descriptive study that consisted of two phases. A macroscopic phase in which 11 cadaveric hearts were extracted and coronary dominance and length of the anterior interventricular artery (AIA), the right coronary artery (RCA) and the circumflex artery (CXA) were determined. In the microscopic phase a total of 77 segments of these arteries were obtained and the luminal diameter, wall thickness, and amount of elastic fibers and the presence and size of the atheroma were determined. Right coronary dominance was the most frequent. Total vessel length was 15.65±1.17 cm for the AIA, 12.67±2.02 cm for the RCA and 8.79±2.5 cm for the CXA. Diameters ranged from 2.3 mm in the proximal segments and between 1.1 mm to 1.8 mm in the distal segments. Wall thickness in the proximal segments was between 354 µm and 396 µm and in the distal segments it ranged from 120 µm to 305 µm. The amount of elastic fibers showed that they were muscular arteries. Atheromas were present in 35% in the CXA, and in 32.5% in the AIA and the RCA. The largest ones were found in the proximal segments. This study examined the morphology and morphometry of the segments of the coronary arteries that are more frequently occluded. It provides information on the most significant parameters to be considered for election of the vascular graft in myocardial revascularization surgery