Medical students' knowledge about human papillomavirus (HPV), HPV vaccine and head and neck cancer.

The Human Papillomavirus (HPV) is a sexually transmitted infection that significantly affects the population worldwide. HPV preventive methods include vaccination, prophylactics, and education. Different types of cancers associated with HPV usually take years or decades to develop after infections, such as Head and Neck Cancer(HNC). Therefore, HPV prevention can be considered cancer prevention. A sample of medical students in Puerto Rico was evaluated to assess their knowledge about HPV, HPV vaccine, and HNC through two previously validated online questionnaires composed of 38 dichotomized questions, we measured HPV, HPV vaccination(HPVK), and HNC knowledge (HNCK). Out of 104 students surveyed, the mean HPVK score obtained was 20.07/26, SD = 3.86, while the mean score for HNCK was 6.37/12, SD = 1.78. Bidirectional stepwise regression showed study year and HPV Vaccine name had been the most influential variables on HPVK and HNCK. MS1 participants scored lower than MS2-MS4 participants, with no significant difference between MS2-MS4 scores. The results reveal knowledge gaps in HPV/HPV Vaccine and HNC among surveyed medical students. Our findings also suggest an association between knowledge of personal vaccination status, self-perceived risk, and how uncertainty in these factors may affect the medical students' understanding of HPV, HPV vaccination, and associated cancers.

Drought stress and hurricane defoliation influence mountain clouds and moisture recycling in a tropical forest.

Mountain ranges generate clouds, precipitation, and perennial streamflow for water supplies, but the role of forest cover in mountain hydrometeorology and cloud formation is not well understood. In the Luquillo Experimental Forest of Puerto Rico, mountains are immersed in clouds nightly, providing a steady precipitation source to support the tropical forest ecosystems and human uses. A severe drought in 2015 and the removal of forest canopy (defoliation) by Hurricane Maria in 2017 created natural experiments to examine interactions between the living forest and hydroclimatic processes. These unprecedented land-based observations over 4.5 y revealed that the orographic cloud system was highly responsive to local land-surface moisture and energy balances moderated by the forest. Cloud layer thickness and immersion frequency on the mountain slope correlated with antecedent rainfall, linking recycled terrestrial moisture to the formation of mountain clouds; and cloud-base altitude rose during drought stress and posthurricane defoliation. Changes in diurnal cycles of temperature and vapor-pressure deficit and an increase in sensible versus latent heat flux quantified local meteorological response to forest disturbances. Temperature and water vapor anomalies along the mountain slope persisted for at least 12 mo posthurricane, showing that understory recovery did not replace intact forest canopy function. In many similar settings around the world, prolonged drought, increasing temperatures, and deforestation could affect orographic cloud precipitation and the humans and ecosystems that depend on it.

Reassessing rainfall in the Luquillo Mountains, Puerto Rico: Local and global ecohydrological implications.

Mountains receive a greater proportion of precipitation than other environments, and thus make a disproportionate contribution to the world's water supply. The Luquillo Mountains receive the highest rainfall on the island of Puerto Rico and serve as a critical source of water to surrounding communities. The area's role as a long-term research site has generated numerous hydrological, ecological, and geological investigations that have been included in regional and global overviews that compare tropical forests to other ecosystems. Most of the forest- and watershed-wide estimates of precipitation (and evapotranspiration, as inferred by a water balance) have assumed that precipitation increases consistently with elevation. However, in this new analysis of all known current and historical rain gages in the region, we find that similar to other mountainous islands in the trade wind latitudes, leeward (western) watersheds in the Luquillo Mountains receive lower mean annual precipitation than windward (eastern) watersheds. Previous studies in the Luquillo Mountains have therefore overestimated precipitation in leeward watersheds by up to 40%. The Icacos watershed, however, despite being located at elevations 200-400 m below the tallest peaks and to the lee of the first major orographic barrier, receives some of the highest precipitation. Such lee-side enhancement has been observed in other island mountains of similar height and width, and may be caused by several mechanisms. Thus, the long-reported discrepancy of unrealistically low rates of evapotranspiration in the Icacos watershed is likely caused by previous underestimation of precipitation, perhaps by as much as 20%. Rainfall/runoff ratios in several previous studies suggested either runoff excess or runoff deficiency in Luquillo watersheds, but this analysis suggests that in fact they are similar to other tropical watersheds. Because the Luquillo Mountains often serve as a wet tropical archetype in global assessments of basic ecohydrological processes, these revised estimates are relevant to regional and global assessments of runoff efficiency, hydrologic effects of reforestation, geomorphic processes, and climate change.

Notes on quantitative structure-properties relationships (QSPR) (1): A discussion on a QSPR dimensionality paradox (QSPR DP) and its quantum resolution.

Classical quantitative structure-properties relationship (QSPR) statistical techniques unavoidably present an inherent paradoxical computational context. They rely on the definition of a Gram matrix in descriptor spaces, which is used afterwards to reduce the original dimension via several possible kinds of algebraic manipulations. From there, effective models for the computation of unknown properties of known molecular structures are obtained. However, the reduced descriptor dimension causes linear dependence within the set of discrete vector molecular representations, leading to positive semi-definite Gram matrices in molecular spaces. To resolve this QSPR dimensionality paradox (QSPR DP) here is proposed to adopt as starting point the quantum QSPR (QQSPR) computational framework perspective, where density functions act as infinite dimensional descriptors. The fundamental QQSPR equation, deduced from employing quantum expectation value numerical evaluation, can be approximately solved in order to obtain models exempt of the QSPR DP. The substitution of the quantum similarity matrix by an empirical Gram matrix in molecular spaces, build up with the original non manipulated discrete molecular descriptor vectors, permits to obtain classical QSPR models with the same characteristics as in QQSPR, that is: possessing a certain degree of causality and explicitly independent of the descriptor dimension.

Simulation of photoelectron spectra with anharmonicity fully included: Application to the X 2A2<--X 1A1 band of furan.

Using a new unconventional procedure for calculating Franck-Condon factors with anharmonicity fully included the X 2A2<--X 1A1 band in the photoelectron spectrum of furan (and deuterated furan) was simulated at the second-order perturbation theory level. All 21 vibrational modes were considered but, in the end, only 4 are required to accurately reproduce the spectrum. Except for our own recent work on ethylene such calculations have been previously limited to tri- or tetraatomic molecules. Most of the effect of anharmonicity is accounted for in first order, although second-order corrections to the vibrational frequencies are important. Based on these simulations we were able to improve upon and extend previous assignments as well as suggest further measurements.

Linfangioma óseo: presentación de dos pacientes / Bone lymphangioma: report of 2 cases

Se presentan las historias clínicas de dos pacientes con diagnóstico de Linfangioma óseo, el cual es un tumor benigno formado por vasos linfáticos, cuya etiología es desconocida. Las lesiones muestran variabilidad en cuanto a tamaño, sitio y hueso afectado, ya que involucra desde los huesos de la calota, huesos largos y cortos. la evolución de las lesiones puede ser estacionaria o avanzar hasta la total desaparición del hueso