Coat protein of a whitefly-vectored plant virus as a delivery system to target whitefly.

The sweet potato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is responsible for significant crop losses and presents one of the greatest challenges for global agricultural pest management. Management of whitefly populations and associated plant viral diseases is hindered by widespread whitefly resistance to chemical insecticides. An alternative control approach involves the use of insect-specific neurotoxins, but these require delivery from the whitefly gut into the haemocoel. Here we demonstrate that the coat protein (CP) of a begomovirus, Tomato yellow leaf curl virus, is sufficient for delivery of fused proteins into the whitefly haemocoel without virion assembly. Following feeding on the recombinant CP-P-mCherry fusion (where -P- is a proline-rich linker), mCherry fluorescence was detected in the dorsal aorta and pericardial cells of the whitefly, but not in those of whitefly fed on negative control treatments, indicating effective CP-mediated delivery of mCherry into the whitefly haemocoel. Significant mortality was observed in whiteflies fed on a fusion of CP-P to the insect-specific neurotoxin Hv1a, but not in whiteflies fed on CP-P fused to a disarmed Hv1a mutant. Begomovirus coat protein - insect neurotoxin fusions hold considerable potential for transgenic resistance to whitefly providing valuable tools for whitefly management.

White-crested elaenias (Elaenia albiceps chilensis) breeding across Patagonia exhibit similar spatial and temporal movement patterns throughout the year.

For migratory birds, events happening during any period of their annual cycle can have strong carry-over effects on the subsequent periods. The strength of carry-over effects between non-breeding and breeding grounds can be shaped by the degree of migratory connectivity: whether or not individuals that breed together also migrate and/or spend the non-breeding season together. We assessed the annual cycle of the White-crested Elaenia (Elaenia albiceps chilensis), the longest-distance migrant flycatcher within South America, which breeds in Patagonia and spends the non-breeding season as far north as Amazonia. Using light-level geolocators, we tracked the annual movements of elaenias breeding on southern Patagonia and compared it with movements of elaenias breeding in northern Patagonia (1,365 km north) using Movebank Repository data. We found that elaenias breeding in southern Patagonia successively used two separate non-breeding regions while in their Brazilian non-breeding grounds, as already found for elaenias breeding in the northern Patagonia site. Elaenias breeding in both northern and southern Patagonia also showed high spread in their non-breeding grounds, high non-breeding overlap among individuals from both breeding sites, and similar migration phenology, all of which suggests weak migratory connectivity for this species. Elucidating the annual cycle of this species, with particular emphasis on females and juveniles, still requires further research across a wide expanse of South America. This information will be critical to understanding and possibly predicting this species' response to climate change and rapid land-use changes.

Two thousand years of garden urbanism in the Upper Amazon.

A dense system of pre-Hispanic urban centers has been found in the Upano Valley of Amazonian Ecuador, in the eastern foothills of the Andes. Fieldwork and light detection and ranging (LIDAR) analysis have revealed an anthropized landscape with clusters of monumental platforms, plazas, and streets following a specific pattern intertwined with extensive agricultural drainages and terraces as well as wide straight roads running over great distances. Archaeological excavations date the occupation from around 500 BCE to between 300 and 600 CE. The most notable landscape feature is the complex road system extending over tens of kilometers, connecting the different urban centers, thus creating a regional-scale network. Such extensive early development in the Upper Amazon is comparable to similar Maya urban systems recently highlighted in Mexico and Guatemala.

Beyond the Scalpel: Assessing ChatGPT's potential as an auxiliary intelligent virtual assistant in oral surgery.

AI has revolutionized the way we interact with technology. Noteworthy advances in AI algorithms and large language models (LLM) have led to the development of natural generative language (NGL) systems such as ChatGPT. Although these LLM can simulate human conversations and generate content in real time, they face challenges related to the topicality and accuracy of the information they generate. This study aimed to assess whether ChatGPT-4 could provide accurate and reliable answers to general dentists in the field of oral surgery, and thus explore its potential as an intelligent virtual assistant in clinical decision making in oral surgery. Thirty questions related to oral surgery were posed to ChatGPT4, each question repeated 30 times. Subsequently, a total of 900 responses were obtained. Two surgeons graded the answers according to the guidelines of the Spanish Society of Oral Surgery, using a three-point Likert scale (correct, partially correct/incomplete, and incorrect). Disagreements were arbitrated by an experienced oral surgeon, who provided the final grade Accuracy was found to be 71.7%, and consistency of the experts' grading across iterations, ranged from moderate to almost perfect. ChatGPT-4, with its potential capabilities, will inevitably be integrated into dental disciplines, including oral surgery. In the future, it could be considered as an auxiliary intelligent virtual assistant, though it would never replace oral surgery experts. Proper training and verified information by experts will remain vital to the implementation of the technology. More comprehensive research is needed to ensure the safe and successful application of AI in oral surgery.

Estimation of parasitaemia in imported falciparum malaria using the results of a combined rapid diagnostic test. No big help from haematological parameters.

BACKGROUND: Microscopy continues to be the mainstay for the evaluation of parasitaemia in malaria but requires laboratory support and microbiological experience. Other fast and simple methods are necessary. METHODS: A retrospective observational study of imported malaria treated from July-2007 to December-2020 was carried out to evaluate the association between the degree of parasitaemia and both rapid diagnostic tests (RDT) reactivity patterns and haematological parameters. Plasmodium falciparum monoinfections diagnosed by peripheral blood smear and/or polymerase chain reaction (PCR),which also had a positive RDT result in the same blood sample, were included in the study. RESULTS: A total of 273 patients were included. Most of them were male (n = 256; 93.8%) and visiting friends and relatives (VFR) travellers (n = 252; 92.3%). Patients with plasmodial lactate dehydrogenase (pLDH) or aldolase and histidine-rich protein 2 (HRP-2) co-reactivity (Pan/Pf pattern) had a parasitaemia range between 0 and 37% while those with just HRP-2 reactivity (P. falciparum pattern) had ranges between 0 and 1%. Not a single case of P. falciparum pattern was found for parasitaemia ranges greater than 1%, showing a negative predictive value of 100% for high parasitaemia. All the correlations between haematological parameters and parasitaemia resulted to be weak, with a maximum rho coefficient of -0.35 for lymphocytes and platelets, and of 0.40 for neutrophils-to-lymphocytes count ratio. Multivariate predictive models were constructed reflecting a poor predictive capacity. CONCLUSIONS: The reactivity pattern of RDT allows a rapid semi-quantitative assessment of P. falciparum parasitaemia in travellers with imported malaria, discriminating patients with lower parasite loads. Haematological parameters were not able to estimate parasitaemia with sufficient precision.

Next-Generation Pedal: Integration of Sensors in a Braking Pedal for a Full Brake-by-Wire System.

This article presents a novel approach to designing and validating a fully electronic braking pedal, addressing the growing integration of electronics in vehicles. With the imminent rise of brake-by-wire (BBW) technology, the brake pedal requires electronification to keep pace with industry advancements. This research explores technologies and features for the next-generation pedal, including low-power consumption electronics, cost-effective sensors, active adjustable pedals, and a retractable pedal for autonomous vehicles. Furthermore, this research brings the benefits of the water injection technique (WIT) as the base for manufacturing plastic pedal brakes towards reducing cost and weight while enhancing torsional stiffness. Communication with original equipment manufacturers (OEMs) has provided valuable insights and feedback, facilitating a productive exchange of ideas. The findings include two sensor prototypes utilizing inductive technology and printed-ink gauges. Significantly, reduced power consumption was achieved in a Hall-effect sensor already in production. Additionally, a functional BBW prototype was developed and validated. This research presents an innovative approach to pedal design that aligns with current electrification trends and autonomous vehicles. It positions the braking pedal as an advanced component that has the potential to redefine industry standards. In summary, this research significantly contributes to the electronic braking pedal technology presenting the critical industry needs that have driven technical studies and progress in the field of sensors, electronics, and materials, highlighting the challenges that component manufacturers will inevitably face in the forthcoming years.

Validación del inventario de socialización organizacional en México

Objetivo: Generar una versión válida y confiable en población mexicana del inventario de socialización organizacional de taormina (OSI), validada por Bravo-Sánz (2001). Método: A partir de los puntajes obtenidos en el OSI se realizó en AMOS 23,0 un análisis factorial confirmatorio con máxima verosimilitud con los 20 ítems y factores originales (entrenamiento, apoyo de los compañeros, comprensión y perspectivas de futuro). La muestra se compuso por 489 trabajadores con una media de edad de 36 años. Resultados: Los resultados del AFC mostraron que, aunque el modelo se ajustaba de forma adecuada con los ítems originales, la validez y confiabilidad de constructo solo se obtuvieron al disminuir la cantidad de factores desechando el de comprensión. Se obtuvo un ajuste de modelo CMIN/DF= 2,02, CFI=0,97, AGFI= 0,94, RMSEA 0,046, SRMR 0,038. Conclusiones: Se logró un modelo válido (AVE >0,50) en todos sus factores y confiable (CR>0,74) en todos sus elementos con un total de 11 ítems con sus baremos para población. Esta versión del inventario de socialización puede ser empleada en población mexicana, lo cual incidirá en investigaciones organizacionales, administrativas, psicológicas con diversas temáticas para determinar la adaptación a la cultura organizacional.

Objective: The objective of this research was to generate a valid and reliable version of the taormina organizational socialization inventory (OSI) for the Mexican population, validated by Bravo-Sánz (2001). Method: Based on the scores obtained in the OSI, a confirmatory factor analysis was carried out in AMOS 23,0 with maximum likelihood with the 20 original items and factors (training, peer support, understanding and future perspectives). The sample was made up of 489 workers with a mean age of 36 years. Results: The results of the CFA showed that, although the model adjusted adequately with the original items, the validity and reliability of the construct were only obtained by reducing the number of factors, discarding the comprehension factor. A model fit CMIN/DF= 2,02, CFI=0,97, AGFI= 0,94, RMSEA 0,046, SRMR .038 was obtained. Conclusions: A valid model (AVE >0,50) was achieved in all its factors and a reliable one (CR>0,74) in all its elements with a total of 11 items with their scales for the population. This version of the socialization inventory can be used in the Mexican population, which will affect organizational, administrative, psychological research with various themes to determine adaptation to organizational culture.

Bienestar psicológico, salud mental y pautas percibidasde apego: estudio comparativo entre mexicanos y estadounidenses durante la pandemia COVID 19 / Psychological well-being, Mental health and patterns of perceived attachment: a comparative study between Mexicans and Americans during the COVID 19 Pandemic

Psychological Well-Being, Mental Health and Patterns of Perceived Attachment: A Comparative Study between Mexicans and Americans during the COVID 19 Pandemic. A correlational and comparative study was carried out on Psychological Well-Being, elements of mental health, and Patterns of Perceived Attachment in Childhood as a possible protection variable in the COVID-19 pandemic. The total N was 316, of which 161 were Mexican students and 155 Americans. The instruments used were the Psychological Well-being Scale, the Depression Anxiety Stress Inventory, and the Inventory of Perceived Attachment Patterns During Childhood. The results show higher indicators of mental health impairment in young Mexicans compared to Americans: depression 76% vs 20.24%. anxiety 93% vs 38% and stress 68% vs 12.5%. In addition, average positive correlations were identified between Psychological Well-Being and secure attachment and negative correlations with the other forms of attachment. In the Americans, a low positive association was found between secure attachment and self-acceptance, positive relationships (the highest correlated), and the scale’s total. Similarly, disorganized, anxious, and avoidant attachment patterns are negatively correlated with self-acceptance, positive relationships, mastery of the environment, life purposes, and the total. Therefore, we consider that Patterns of Perceived Attachment in Childhood are associated with the elements of mental health such as: anxiety, depression, and stress, and with the levels of psychological well-being experienced during the pandemic. Finally, suggestions of other mediating and protective variables for future research are offered (AU)

Accuracy of Three Serological Techniques for the Diagnosis of Imported Schistosomiasis in Real Clinical Practice: Not All in the Same Boat.

Schistosomiasis is a neglected tropical disease despite of being a major public health problem affecting nearly 240 million people in the world. Due to the migratory flow from endemic countries to Western countries, an increasing number of cases is being diagnosed in non-endemic areas, generally in migrants or people visiting these areas. Serology is the recommended method for screening and diagnosis of schistosomiasis in migrants from endemic regions. However, serological techniques have a highly variable sensitivity. The aim of this study was to evaluate retrospectively the sensitivity of three different serological tests used in real clinical practice for the screening and diagnosis of imported schistosomiasis in sub-Saharan migrant patients, using the detection of schistosome eggs in urine, faeces or tissues as the gold standard. We evaluated three different serological techniques in 405 sub-Saharan patients with confirmed schistosomiasis treated between 2004 and 2022: an enzyme-linked immunosorbent assay (ELISA), an indirect haemagglutination assay (IHA) and an immunochromatographic test (ICT). The overall sensitivity values obtained with the different techniques were: 44.4% for IHA, 71.2% for ELISA and 94.7% for ICT, respectively. According to species, ICT showed the highest sensitivity (S. haematobium: 94%, S. mansoni: 93.3%; and S. intercalatum/guineensis: 100%). In conclusion, our study shows that Schistosoma ICT has the best performance in real clinical practice, when compared to ELISA and IHA, in both S. mansoni and S. haematobium infections.

The association of bicuspid aortic valve on long-term outcome following one-stage repair of aortic arch obstruction associated with ventricular septal defect.

OBJECTIVE: The aim of this study was to evaluate the association of bicuspid aortic valve on contemporary outcomes, including reoperation rates, after one-stage correction for interrupted aortic arch with ventricular septal defect or for aortic coarctation with hypoplastic aortic arch and ventricular septal defect. METHODS: Seventy-four consecutive patients (35 boys, 47% and 39 girls, 53%) with interrupted aortic arch (n = 41, 55%) or aortic coarctation with hypoplastic aortic arch (n = 33, 45%) with ventricular septal defect underwent early one-stage correction. Twenty (27%) patients had bicuspid aortic valve, and the remaining 54 (73%) had a tricuspid aortic valve. The median aortic valve annulus diameter was 6.0 mm (IQR: 2.0). Patients' median age was 7 ± 29 days (range, 2-150); median weight was 3.3 ± 0.7 kg (range, 1.5-6.0), with 21 (28%) patients <3.0 kg. Selective brain perfusion through the innominate artery and selective coronary perfusion through the aortic root during aortic arch reconstruction were used in all patients. Statistical analysis was performed using SPSS version 20.0 software (SPSS Inc., Chicago, IL, USA). RESULTS: The early mortality was 1.3%. One premature neonate died in the hospital with extracorporeal membrane oxygenation after aortic coarctation plus ventricular septal defect repair. There was no further mortality. Median follow-up was 5.7 years (IQR: 10.48). Reinterventions occurred in 36 (49%) patients: balloon angioplasty in 18 (24%) patients, reoperations in 4 (5%) patients, and both in 14 (19%) patients. A total of 86 follow-up procedures were required in these 36 (49%) patients: aortic valve valvulopasty (n = 6, 8%), stent implantation (n = 8, 11%), balloon dilatation (n = 39, 53%), and reoperation (n = 33, 45%). The median time to reinterventions was 9.094 years (SE 0.890). A potential risk factor for reintervention after interrupted aortic arch and aortic coarctation with ventricular septal defect repair was bicuspid aortic valve (p = 0.019, Chi2 (1) = 5.457). In addition, a multivariate Cox analysis with backward selection and significance level <0.015 was applied to all variables that showed significant effects in univariable analyzes. This regression confirmed that bicuspid aortic valve (HR = 0.381, p = .016), and interrupted aortic arch (HR = 0.412, p = 0.043) were predictors of late reintervention. All patients had no obvious neurologic impairment in routine examinations at last follow-up. CONCLUSION: Bicuspid aortic valve was a significant risk factor for valve-related reintervention after one-stage repair for aortic arch obstruction with ventricular septal defect due to later development of stenosis associated with higher late morbidity and mortality. Particularly neonates with bicuspid aortic valve will possibly require reintervention in the future. Regular lifelong cardiac follow-up is recommended.

Socio-demographic parameters and non-cardiac comorbidity related to self-perceived quality of life in young adults after neonatal arterial switch operation for transposition of the great arteries.

Evaluating the relation of non-cardiac comorbidity and socio-demographic factors to physical and mental health-related quality of life (QOL) which has been partially found at elevated risk in young adults after neonatal arterial switch operation (ASO) for transposition of the great arteries (TGA). In a prospective reassessment study, results of 92 unselected young adults (22.8 ± 2.6 years) having undergone evaluation of QOL (SF-36) were related to non-cardiac comorbidity with special respect to neurologic and psychiatric comorbidity and to socio-demographic parameters. Neurologic (14%) contrary to psychiatric comorbidities (6.5%) were more frequent than in the general population. The educational level was higher, the rate of unemployment was double as high compared to the average German population. Significant inverse relations (p = 0.006 to 0.033) existed between physical health domains (physical functioning and general health perception) and non-cardiac, neurologic, and psychiatric comorbidity, as well as correlations between the latter domains and socio-economic status, educational level, and worse employment status (Spearman 0.22-0.41, p < 0.0001 to 0.036). Mental health domains (vitality, social functioning, psychical health) were significantly inversely related with neurologic and psychiatric comorbidity (p = 0.002 to 0.048) and correlated with higher educational level (Spearman 0.25, p = 0.019). Neurologic and psychiatric comorbidities and socio-demographic parameters are significant risk factors for a reduced QOL concerning physical and mental health in young adults with TGA after ASO. Standardized QOL measurement should be part of routine screening programs to detect subclinical physical, neurodevelopmental, and psychosocial comorbidity.

Role of Acrostyle Cuticular Proteins in the Retention of an Aphid Salivary Effector.

To avoid the activation of plant defenses and ensure sustained feeding, aphids are assumed to use their mouthparts to deliver effectors into plant cells. A recent study has shown that effectors detected near feeding sites are differentially distributed in plant tissues. However, the precise process of effector delivery into specific plant compartments is unknown. The acrostyle, a cuticular organ located at the tip of maxillary stylets that transiently binds plant viruses via its stylin proteins, may participate in this specific delivery process. Here, we demonstrate that Mp10, a saliva effector released into the plant cytoplasm during aphid probing, binds to the acrostyles of Acyrthosiphon pisum and Myzus persicae. The effector probably interacts with Stylin-03 as a lowered Mp10-binding to the acrostyle was observed upon RNAi-mediated reduction in Stylin-03 production. In addition, Stylin-03 and Stylin-01 RNAi aphids exhibited changes in their feeding behavior as evidenced by electrical penetration graph experiments showing longer aphid probing behaviors associated with watery saliva release into the cytoplasm of plant cells. Taken together, these data demonstrate that the acrostyle also has effector binding capacity and supports its role in the delivery of aphid effectors into plant cells.

Are Tourists Facilitators of the Movement of Free-Ranging Dogs?

Dogs are the most abundant carnivores on earth and, as such, negatively impact wildlife. Free-ranging dogs roam in many protected areas, which in turn are often tourist destinations. Whether tourists influence their roaming is largely unexplored but highly relevant to wildlife conservation. To address this question, we obtained (i) 81 completed questionnaires from tourists on their experience with free-ranging dogs in the remote Cape Horn Biosphere Reserve, Chile, and (ii) photographs of three camera-traps placed next to trekking trails (n = 87 trap days). A third of the participants were followed by dogs for up to four days, and 39% saw free-ranging dogs on their hikes, but neither feeding dogs nor fear of them had any influence on whether tourists were followed by dogs. Camera-traps yielded 53 independent dog sequences, recorded 32 individuals plus 14 unidentified dogs, of which only one was leashed, with a frequency of one dog every 28th person. In 17% of 53 sequences, dogs were photographed together with hikers carrying large backpacks for several-day trips. We conclude that tourists are facilitators for the movement of dogs and highlight the importance of the engagement of the tourism sector in wildlife conservation in and close to protected areas.

Exposición y Desensibilización a la Violencia en Jóvenes Mexicanos en Distintos Contextos Sociales / Exposure and Desensitization to Violence among Mexican Youth from Different Social Contexts

Resumen El objetivo fue conocer la exposición y desensibilización a la violencia en jóvenes de cinco contextos en distintas instituciones educativas y de readaptación social de la ciudad de San Luis Potosí. Método: se realizó un estudio analítico transversal comparativo de 25 instituciones de educación media superior, ubicados en Zonas Rurales (ZR), en Polígonos de Violencia (PV), Cercanas a Polígonos de Violencia (CPV), en Zonas Alejadas de los Polígonos de Violencia (ZAPV), y en un Centro de Internamiento Juvenil (CIJ) con un total de 1720 participantes; 851 (49.5 %) hombres y 869 (50.5%) mujeres. Resultados: Se encontraron medias significativamente más altas en desensibilización a la violencia en participantes del CIJ, seguidos por participantes de las ZAPV, y al final el ZR. Referente a la exposición a la violencia fue mayor en aquellos provenientes de las ZAPV después en jóvenes del CIJ y finalmente los de ZR. Conclusiones: La desensibilización a la violencia se presenta como consecuencia a la exposición de la violencia y las conductas que atentan contra la seguridad social. Finalmente, se encontró que las actividades artísticas y los padres unidos funcionan como factores de protección contra la desensibilización a la violencia.

Abstract The aim of this research was to measure the exposure and desensitization to violence in young people from five contexts in different educational institutions and a Juvenile Detention Center in the city of San Luis Potosí and its surroundings in Mexico. Desensitization to violence is a phenomenon that is generated due to constant exposure to violence, resulting in a decrease in emotional responses, adverse judgments, and opposition to violent acts, it can lead to a normalization of violent acts and with it a minimization of their seriousness, which promotes positive emotions in the individual such as pleasure, fun or entertainment when exposed to said acts or events. Method: a comparative cross-sectional analytical study was carried out in 25 institutions of higher secondary education, located in rural areas and in polygons identified as violent, near to polygons and far from them, and in a Juvenile Detention Center with a total of 1720 male participants. Results: Significantly higher means were found in desensitization to violence in participants from the internment center, later from those of the areas that were initially identified as far from the polygons of violence, and finally the lowest in the rural context. Regarding exposure to violence, it was higher in those participants far from the polygons of violence, then in young people from the internment center, and finally those from the rural context. In addition, of the three areas analyzed, lower levels of schooling were found in people in a situation of internment. Conclusions: Desensitization to violence occurs as a consequence of exposure to violence and behaviors that threaten social security. Also, it was found that artistic activities and being part of a family, with father and mother together, worked as a protective factor against desensitization to violence. Some plausible explanations for these findings are suggested.

Bacteria-derived pesticidal proteins active against hemipteran pests.

Hemipteran pests are among the most important threats to agricultural production. Losses associated with these insects result from both feeding-associated damage and the transmission of plant pathogens by some species. Key among hemipteran pests of agricultural importance are stink bugs, whitefly, aphids and psyllids. While bacteria provide an excellent resource for identification of environmentally benign pesticidal proteins for use against pest insects, relatively few with activity against hemipteran species have been identified. In this comprehensive review including the patent literature, we describe physiological features unique to Hemiptera that may restrict the toxicity of bacterial pesticidal proteins, provide an overview of Hemiptera-active pesticidal proteins and associated structural classes, and summarize biotechnological strategies used for optimization of toxicity against target hemipteran species.

SNAPSHOT USA 2020: A second coordinated national camera trap survey of the United States during the COVID-19 pandemic.

Managing wildlife populations in the face of global change requires regular data on the abundance and distribution of wild animals, but acquiring these over appropriate spatial scales in a sustainable way has proven challenging. Here we present the data from Snapshot USA 2020, a second annual national mammal survey of the USA. This project involved 152 scientists setting camera traps in a standardized protocol at 1485 locations across 103 arrays in 43 states for a total of 52,710 trap-nights of survey effort. Most (58) of these arrays were also sampled during the same months (September and October) in 2019, providing a direct comparison of animal populations in 2 years that includes data from both during and before the COVID-19 pandemic. All data were managed by the eMammal system, with all species identifications checked by at least two reviewers. In total, we recorded 117,415 detections of 78 species of wild mammals, 9236 detections of at least 43 species of birds, 15,851 detections of six domestic animals and 23,825 detections of humans or their vehicles. Spatial differences across arrays explained more variation in the relative abundance than temporal variation across years for all 38 species modeled, although there are examples of significant site-level differences among years for many species. Temporal results show how species allocate their time and can be used to study species interactions, including between humans and wildlife. These data provide a snapshot of the mammal community of the USA for 2020 and will be useful for exploring the drivers of spatial and temporal changes in relative abundance and distribution, and the impacts of species interactions on daily activity patterns. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication.

Predicting malignancy in small testicular lesions.

Introduction: Small testicular lesions ≤20 mm (STL) detected by ultrasound (US), usually non-palpable, have been reported to be benign in up to 80% of cases. Thus, partial orchiectomy with or without frozen section examination and surveillance has been advocated for these kinds of lesions. We seek to report the proportion of benign lesions in testicular tumors ≤20 mm detected by US in our population and explore the predicting factors of malignancy. Material and methods: A retrospective descriptive study of orchiectomies performed for testicular tumors in patients older than 15 years between 2005 and 2019 was performed, including all patients with lesions ≤20 mm on US imaging. Results: A total of 70 patients with STL were included (mean age 34.6 ±10.8 years). Overall, 69% of the lesions were malignant while the smallest lesions (≤10 mm) showed 61% of cancer. Moreover, in the subgroup of non-palpable lesions ≤10 mm, 50% were malignant. Multifocal tumors were found in 18 subjects with a malignancy rate of 88%. There was a significant association between maximum size on US, multifocality and malignancy. Neither tumor markers nor palpability foretold a malignant lesion. A predictive model including size and multifocality was created showing a positive predictive value of 83.3%. Conclusions: US maximum size and multifocality were predictors of malignancy in STL. However, even the smallest lesions showed a 50% chance of being malignant, thus surgery with or without intraoperative biopsy is warranted in most cases.