In spite of enormous diversity in tree species, dendrochronological records in the tropical Andes are very scarce. Therefore, it is necessary to increase the search for new tree species with high dendrochronological characteristics in the tropical Andes, including the humid Puna of Peru. We present the first tree-ring chronology from Polylepis rodolfo-vasquezii, a recently described tree species in the Central Andes of Peru between 4000 and 4400 m elevation. Fifty trees were sampled in the district of Comas, Peru. After establishing the anatomical characteristics that delimit the annual growth rings, we developed a ring-width chronology by applying conventional dendrochronological techniques. The chronology covers the period 1869–2015 (157 years) and is well replicated from 1920 to present (> 20 samples). The statistics used to evaluate the quality of the chronology indicate that the P...

The authors thank Rosana Ordaya and Johan Lázaro for their help in the field, Ricardo Rodríguez and Luiz Santin for the histological cuts, and Wil-fredo Bulege for the administrative support of the project. We also thank two anonymous reviewers for their valuable comments and Anabela Bonada for the writing and language editing. This study was financed by the National Council for Science, Technology and Technological Innovation-Peru (Project N° 147-2015-FONDECYT-DE, Project N° 039-2019-FONDECYT-BM-INC-INV).

Se realizaron mediciones biométricas, análisis de diámetro y longitud en 71 vicuñas esquiladas en la zona nuclear de la Reserva Nacional de Pampa Galera, Bárbara D’ Achile. Las medidas corporales evaluadas demuestran que no existe dimorfismo sexual en vicuñas y que las variaciones se deben principalmente a la edad del animal. Se encontró que la vicuña adulta muestra una altura a la cruz, diámetro torácico, longitud del animal y altura a la cabeza de 85.2 ± 4.97, 86.47 ± 5.0, 79.6 ± 4.9 y 125.09 ± 6.33 cm, respectivamente. El diámetro de fibra de vicuña promedio de toda la evaluación resultó ser 11.64 ± 1.3µ, encontrándose una interacción entre sexo y edad del animal, siendo el menor diámetro  para los animales jóvenes. El promedio de longitud de la fibra de vellón de vicuña fue de 1.083+0.25 pulgadas e indiferente a los factores de sexo, edad y zona corporal.

Poster presented at the 2021 CEDAR Virtual Workshop, June 20-25.

Es de gran importancia en el sistema agropecuario estudiar las malezas tóxicas y sus efectos en el ganado. El objetivo fue identificar malezas tóxicas para el ganado en el valle del Mantaro, Junín. Establecimiento de pastos y caminos de monitoreo, fueron evaluados en el 2012 y 2013 respectivamente. En el establecimiento de pastizales se realizaron evaluaciones de 1 ha de los potreros Octoberfest en cuadrantes de 0,25m2, las muestras se tomaron al azar. En total se registraron 50 especies de malezas incluidas en 39 géneros y 16 familias. De las cuales el 44 % son tóxicas. Según el índice de valor de importancia (IVI), las especies más importantes fueron: Brassica rapa subsp. campestris, Veronica persica, Capsella bursa- pastoris y Fuertesimalva leptocalyx.

Introducción: la tuberculosis es la enfermedad infecciosa más importante del ser humano por su alta incidencia mundial, constituyendo un problema de salud pública. Los conocimientos, actitudes y prácticas sobre ella han sido evaluados en estudiantes universitarios y profesionales de ciencias de la salud, pero otros han sido desatendidos. Objetivos: evaluar conocimientos, actitudes y prácticas sobre tuberculosis en estudiantes que no pertenecen a ciencias de la salud de una universidad peruana. Métodos: estudio transversal analítico, se encuestó estudiantes de la Universidad Nacional del Centro del Perú usando un cuestionario estructurado. Luego se caracterizó cada una de las secciones y buscó diferencias según las características de los alumnos mediante los modelos lineales generalizados. Resultados: de 631 estudiantes, 54,7 % fueron mujeres, 66,6 % obtuvo puntaje bajo en la...

Data from a network of high-frequency (HF) beacons deployed in Peru are used to estimate the regional ionospheric electron density in a volume. Pseudorange, accumulated carrier phase, and signal power measurements for each of the 36 ray paths provided by the network at a 1 min cadence are incorporated in the estimates. Additional data from the Jicamarca incoherent scatter radar, the Jicamarca sounder, and GPS receivers can also be incorporated. The electron density model is estimated as the solution to a global optimization problem that uses ray tracing in the forward model. The electron density is parametrized in terms of B-splines in the horizontal direction and generalized Chapman functions or related functions in the vertical. Variational sensitivity analysis has been added to the method to allow for the utilization of the signal power observable which gives additional information ab...

The follicular dynamics was evaluated by ultrasonography in Brown Swiss cattle subjected to a protocol of synchronization of estrus with progestogens in the Peruvian highlands. Three groups of Brown Swiss cattle of nine females each were evaluated. The groups were: lactating cows (<120 and >260 days in milk) and heifers. For synchronization, on day 0 a progesterone-based intravaginal device was applied, and 2 mg estradiol benzoate was injected, on day 8 the device was removed and 0.15 mg cloprostenol and 400 IU eCG were applied, and on day 10 1.05 mg GnRH was applied. Artificial insemination at fixed time was done 12 h after the application of GnRH. The ultrasound evaluation was done on days 8 and 10 to determine the growth rate and maximum diameter of the dominant follicle in the three groups. The follicular growth rate was 2.3 ± 1.5, 2.4 ± 1.8 and 2.3 ± 1.8 mm/day for the grou...

The aim of this study was to determine the applicability of near infrared spectroscopy (NIRS) for the nutritional assessment of two important forage species in the country: alfalfa (Medicago sativa L) and red clover (Trifolium pratense L). For this, 75 samples of alfalfa varieties (SW 8210, WL 625HQ) and 75 of red clover varieties (Quiñequeli, Kendland) obtained from the paddocks of the IVITA El Mantaro Experimental Station, Junín region, Peru were used. Proximal analysis was performed determining the content of crude protein (CP), ether extract (EE), crude fibre (CF), total ash (TA) and neutral detergent fibre (NDF), and the spectrum was captured using NIRS equipment. The calibration and validation models were developed to estimate the predictive capacity using Partial Least Squares (PLS), and the accuracy and precision statistics used were the Correlation Coefficient (R), Determinati...

The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum f...

The follicular dynamics was evaluated by ultrasonography in Brown Swiss cattle subjected to a protocol of synchronization of estrus with progestogens in the Peruvian highlands. Three groups of Brown Swiss cattle of nine females each were evaluated. The groups were: lactating cows (<120 and >260 days in milk) and heifers. For synchronization, on day 0 a progesterone-based intravaginal device was applied, and 2 mg estradiol benzoate was injected, on day 8 the device was removed and 0.15 mg cloprostenol and 400 IU eCG were applied, and on day 10 1.05 mg GnRH was applied. Artificial insemination at fixed time was done 12 h after the application of GnRH. The ultrasound evaluation was done on days 8 and 10 to determine the growth rate and maximum diameter of the dominant follicle in the three groups. The follicular growth rate was 2.3 ± 1.5, 2.4 ± 1.8 and 2.3 ± 1.8 mm/day for the grou...

The aim of this study was to determine the applicability of near infrared spectroscopy (NIRS) for the nutritional assessment of two important forage species in the country: alfalfa (Medicago sativa L) and red clover (Trifolium pratense L). For this, 75 samples of alfalfa varieties (SW 8210, WL 625HQ) and 75 of red clover varieties (Quiñequeli, Kendland) obtained from the paddocks of the IVITA El Mantaro Experimental Station, Junín region, Peru were used. Proximal analysis was performed determining the content of crude protein (CP), ether extract (EE), crude fibre (CF), total ash (TA) and neutral detergent fibre (NDF), and the spectrum was captured using NIRS equipment. The calibration and validation models were developed to estimate the predictive capacity using Partial Least Squares (PLS), and the accuracy and precision statistics used were the Correlation Coefficient (R), Determinati...

The ovarian follicular dynamics monitored by transrectal (TR) and transvaginal (TV) routes in successive waves was studied in 10 llamas older than 4 years, multiparous, without calves at foot, body condition of 3.0, during a period of 90 days in the reproductive season. The Sonostar SS8® ultrasound equipment was used with a linear transducer for transrectal examination and endocavitary microconvex transducer for transvaginal examination, both with a frequency of 6.5 MHz. The inter-wave interval was 20 ± 4.4 and 22.5 ± 5.3 via TR and VT, respectively; the number of follicles per cohort was 5.21 ± 0.92 and 6.38 ± 1.26 for TR and TV, respectively (p=0.0011); the maximum diameter of follicles was 12.49 ± 3.57 mm for TR and 13.56 ± 3.91 mm for TV; the growth rate was 0.70 ± 0.35 and 0.67 ± 0.32 mm/day for TR and TV, respectively. The regression equation for the ratio of the maximum f...

Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high-quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provide a complete record since 1979 and offer a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scales. We developed the first annually resolved precipitation reconstruction for the tropical Andes in Peru, based on tree-ring chronologies of Cedrela and Juglans species. The annual (November–October) reconstruction extends the short instrumental records back to 1817, explaining 68% of the total v...

Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high‐quality instrumental records. Data from the Global Precipitation Climatology Project (GPCP) provide a complete record since 1979 and offer a good representation of rainfall over the tropical Andes. Longer records are needed to improve our understanding of rainfall variability and summer monsoon behavior at various scales. We developed the first annually resolved precipitation reconstruction for the tropical Andes in Peru, based on tree‐ring chronologies of Cedrela and Juglans species. The annual (November–October) reconstruction extends the short instrumental records back to 1817, explaining 68% of the tot...

The aim of this study was to generate calibration equations to predict the nutritional chemical composition of the Italian rye grass (RG) (Lolium multiflorum Lam) by near infrared spectroscopy (NIRS). A total of 75 samples of RG of different harvesting weeks were collected from the IVITA Research Center in Huancayo (Peru). Spectrum capture was performed using NIRS and the chemical analysis was done for reference of the following components: crude protein (CP), ether extract (EE), total ash (CZ), crude fibre (CF) and neutral detergent fibre (NDF). A calibration and validation model by partial least squares (PLS) was developed and the correlation coefficient (R), coefficient of determination (R2), root mean square error of calibration (RMSEC), root mean square error of prediction (RMSEP), ratio range with error (RER) and residual predictive deviation (RPD) were used as statistics of accura...

The aim of this study was to generate calibration equations to predict the nutritional chemical composition of the Italian rye grass (RG) (Lolium multiflorum Lam) by near infrared spectroscopy (NIRS). A total of 75 samples of RG of different harvesting weeks were collected from the IVITA Research Center in Huancayo (Peru). Spectrum capture was performed using NIRS and the chemical analysis was done for reference of the following components: crude protein (CP), ether extract (EE), total ash (CZ), crude fibre (CF) and neutral detergent fibre (NDF). A calibration and validation model by partial least squares (PLS) was developed and the correlation coefficient (R), coefficient of determination (R2), root mean square error of calibration (RMSEC), root mean square error of prediction (RMSEP), ratio range with error (RER) and residual predictive deviation (RPD) were used as statistics of accura...