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The South American camelids are a domesticated species adapted to the high Andes, they are considered as a species of induced ovulation. In these species, so that the release of the oocyte occurs, a neuroendocrine interaction and stimulation during intercourse (which have to lasts on average 18 minutes) is necessary. In recent years, several studies have demonstrated the presence of an inducing factor for the ovulation found in the seminal plasma of the male that is crucial for ovulation to occurs in camelids. From 1968 researches were initiated to confirm and determine the inductor factor. The works have shown that ovulation in alpacas occurs after intramuscular and intravaginal application of seminal plasma. Recent studies showed the luteotropic effect of this factor, which is evidenced by the increase and retention of circulating concentrations of LH, the rapid change in the vascularization of the pre-ovulatory follicle and corpus luteum development, this contributes to the increase of the embryonic survival rate, due to the stimulus that causes this hormone in the pituitary to release LH, triggering an additional luteotropic effect on the corpus luteum with increased secretion of progesterone. At the field, level the results are not as manifest in relation to the results obtained when the ultrasound monitoring is performed. However, the work done by different research groups confirm the contribution of seminal plasma in increasing fertility rates and embryonic survival in domestic camelids such as alpaca and llama.

El desarrollo de las técnicas de reproducción asistida en Camélidos Sudamericanos ha sido establecido con bastante lentitud al compararlas con el desarrollo que han tenido en otras especies como son los rumiantes. Sin embargo técnicas como superovulación, transferencia de embriones y fecundación in vitro han sido abordadas en los últimos años con resultados bastante alentadores y que podrán en un futuro hacer posible de uso en forma comercial. Similar a los rumiantes las respuestas a los protocolos de superovulación continúan siendo muy variables a pesar de tener un control de la actividad ovárica al comienzo de los mismos. La recuperación de blastocistos eclosionados mediante lavado uterino continúa siendo una limitante para poder manipular al embrión posterior a su colección con otras metodologías como congelación o vitrificación. Un gran paso se ha realizado en lo que respecta a los métodos de colección de semen y su uso para la inseminación artificial o para fecundación in vitro. Así también, se ha logrado de obtener ovocitos de animales vivos utilizando punción folicular guiada por ecografía transvaginal. Quizás el impedimento más complejo para lograr un avance significativo del método de fecundación in vitro has sido la escasez en la obtención de ovocitos de matadero, una fuente muy importante de material que pudiera ser utilizado para investigación de la misma forma que lo ha sido para los sistemas in vitro en rumiantes. La intención de esta revisión es dar a conocer los principales protocolos de superovulación que han sido desarrollados hasta la fecha en llamas y alpacas.

We examine the correlation between modern human capital and income among adult men in four foraging-horticultural societies of Bolivia. Despite their remote location, we find results similar to those found in developed nations. We find that: (a) education correlates with 4.5% higher overall income and with 5.9% higher wages and math skills correlates with 13.5% higher cash income, and (b) the positive correlation between education or math skills and income is higher among households closer to market towns. The high returns to modern human capital even in highly autarkic economies might explain why people in those societies reduce investments in the accumulation of traditional folk knowledge.

Immune function is a central component of maintenance effort, and it provides critical protection against the potentially life threatening effects of pathogens. However, immune defenses are energetically expensive, and the resources they consume are not available to support other activities related to growth and/or reproduction. In our study we use a life history theory framework to investigate tradeoffs between maintenance effort and growth among children in a remote area of Amazonian Bolivia. Baseline concentrations of C-reactive protein (CRP) were measured in 309 2- to 10-year olds as an indicator of immune activation, and height was measured at baseline and three months later. Elevated CRP at baseline predicts smaller gains in height over the subsequent three months, with the costs to growth particularly high for 2- to 4-year olds and for those with low energy reserves (in the form of body fat) at the time of immunostimulation. These results provide evidence for a significant tradeoff between investment in immunity and growth in humans, and highlight an important physiological mechanism through which maintenance effort may have lasting effects on child growth and development. KEY WORDS ecological immunology; human growth and development; acute phase response; life history theory; infectious disease; Amazonia

Infectious disease is a major global determinant of child morbidity and mortality, and energetic investment in immune defenses (even in the absence of overt disease) is an important life-history variable, with implications for human growth and development. This study uses a biomarker of immune activation (C-reactive protein) to investigate an important aspect of child health among the Tsimane', a relatively isolated Amerindian population in lowland Bolivia. Our objectives are twofold: 1) to describe the distribution of CRP by age and gender in a cross-sectional sample of 536 2-15-year-olds; and 2) to explore multiple measures of pathogen exposure, economic resources, and acculturation as predictors of increased CRP. The median blood spot CRP concentration was 0.73 mg/1, with 12.9% of the sample having concentrations greater than 5 mg/L, indicating a relatively high degree of immune activation in this population. Age was the strongest predictor of CRP, with the highest concentrations found among younger individuals. Increased CRP was also associated with higher pathogen exposure, lower household economic resources, and increased maternal education and literacy. The measurement of CRP offers a direct, objective indicator of immune activation, and provides insights into a potentially important pathway through which environmental quality may shape child growth and health. KEY WORDS infectious disease; innate immunity; acute-phase response; growth and development; C-reactive protein; Bolivia

This study examines patterns of growth and nutritional status of indigenous Tsimane' children under 9 years of age (n = 199 boys and 210 girls), based on a cross-sectional sample from 58 villages from the Beni Deparment of lowland Bolivia. Compared with US children, Tsimane' children are quite short, with linear growth tracking at or below the US 5th centile in both sexes. The prevalence of low height-for-age ('stunting;' HA Z-scores [less than or equal to] -2) is 52% in boys and 43% in girls. In contrast, weight-for-height in Tsimane' children approximates the US median, with the prevalence of low weight-for-height ('wasting'; WH Z-scores [less than or equal to] -2) being only 4% and 6% in boys and girls, respectively. Tsimane' boys and girls are leaner than their US peers, but their levels of body fatness are not so low as to indicate severe energy stress. Arm muscularity of Tsimane' children is similar to that of their US age peers, and this suggests that they are not experiencing acute protein malnutrition. Variation in measures of nutritional status of Tsimane' children is modestly correlated with village-level differences. Degree of isolation, as measured by distance to urban centers or to primary forest, was not a strong predictor of children's anthropometric status. Rather, in both boys and girls, nutritional status was most strongly associated with number of teachers in the village, a measure of access to education. Comparative analyses indicate that high levels of statural growth stunting are common among indigenous populations throughout lowland South America. This problem appears to be largely attributable to poor dietary quality (diets low in key micronutrients) and high disease loads. Further research is needed to identify the specific causes and potential interventions for the high rates of childhood growth stunting in this region. KEY WORDS anthropometry; stature; weight; skinfolds; Amazonia; diet quality

To preserve humanity's patrimony and diversity and avoid misappropriation by outsiders, laws should protect indigenous knowledge. Firms producing pharmaceutical, agricultural, and cosmetic goods have used ethnobotanical knowledge of indigenous people [...]

Over the last decades, native Amazonians have put increasing pressure on animal wildlife owing to growth in demand. Across societies, household monetary income and wealth shape food consumption; hence, so it is natural to ask what effect might these variables have on the demand for wildlife consumption among native Amazonians, particularly as they gain a stronger foothold in the market economy and increasing de jure stewardship over their territories. Prior estimates of the effects of household monetary income and household wealth on wildlife consumption among native Amazonians have relied on cross-sectional data and produced unclear results. The goal of this research was to improve the precision of previous estimates by drawing on a larger sample and on longitudinal data. The analysis draws on a dataset composed of five consecutive annual surveys (2002–2006, inclusive) from 324 households in a native Amazonian society of foragers and farmers in Bolivia (Tsimane'). Multiple regression analysis is used to estimate the association between wildlife consumption and monetary income and wealth. Wildlife consumption bore a positive association with the level of household wealth and no significant association with household monetary income. Among Tsimane', the main internal threat to wildlife conservation in the short run will likely arise from increases in wealth, probably from the enhanced capacity that selected physical assets (e.g. guns) have in the capture of animal wildlife. [ABSTRACT FROM AUTHOR]

Research with humans and non-human primate species has found an association between social rank and individual health. Among humans, a robust literature in industrial societies has shown that each step down the rank hierarchy is associated with increased morbidity and mortality. Here, we present supportive evidence for the social gradient in health drawing on data from 289 men (18+ years of age) from a society of foragers-farmers in the Bolivian Amazon (Tsimane'). We use a measure of social rank that captures the locally perceived position of a man in the hierarchy of important people in a village. In multivariate regression analysis we found a positive and statistically significant association between social rank and three standard indicators of nutritional status: body mass index (BMI), mid-arm circumference, and the sum of four skinfolds. Results persisted after controlling for material and psychosocial pathways that have been shown to mediate the association between individual socioeconomic status and health in industrial societies. Future research should explore locally-relevant psychosocial factors that may mediate the association between social status and health in non-industrial societies. [ABSTRACT FROM AUTHOR]

Globally, challenges with water and food are two of the most pressing problems people face. Yet hydrologically water-rich environments and rural environments are often overlooked in these discussions due to abundance of natural water resources. Here we test the relationship between water and food insecurity among 270 Tsimane' households in the Bolivian Amazon. Water challenges were evaluated with the Household Water Insecurity Experiences Scale (HWISE), water quality perception, objective water quality analyses, and water access via the JMP drinking water ladder. Food insecurity was measured with the Household Food Insecurity Access Scale (HFIAS), and quantitative measures of food frequency recall were used to further test the water and food insecurity relationship. Using multilevel mixed-effects linear regression, each point increase in HWISE score was associated with 0.47 point (95 % CI: 0.30, 0.62, p < 0.001) higher food insecurity, and households with access to improved water sources had between 1.25 and 1.36 points (95 % CI: -2.61, -0.01, p < 0.05) lower food insecurity compared to households reliant on surface water. These relationships held true independent of quantitative measures of both fish and meat consumption. Using mixed-effects logistic regression analyses, each point increase in HWISE score was associated with 43 % (95 % CI: 1.25-1.66, p < 0.001) increased odds of experiencing severe food insecurity. Households changing what was eaten due to experienced water problems was associated with 2.33 points (95 % CI: 0.41, 4.25, p < 0.05) higher food insecurity. This relationship held true independent of perceived water quality, indicating other structural water problems may be important here in the household water and food insecurity relationship. These results demonstrate that even in water-rich environments, like the Amazon, water and food insecurity are interconnected. Further, despite the challenging conditions, equitable structural interventions, like the development of improved water infrastructure, are critical for the provision of clean drinking water and may simultaneously help alleviate food insecurity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

What makes an odour pleasant or unpleasant? The inherent properties of the constituent chemical compounds, or the nose of the beholder, driven by idiosyncratic differences and culture-specific learning? Here, 582 individuals, including Tanzanian Hadza hunter-gatherers, Amazonian Tsimane' horticulturalists, Yali from the Papuan highlands and two industrialized populations (Poles, Malaysians), rated the pleasantness of 15 odour samples. We find considerable similarities in odour assessments across cultures, but our data do not fully support a claim regarding the universality of smell preferences. Despite cross-cultural similarities in olfactory assessments, probably driven by odour properties, we suggest that odour availability in ecological and cultural niches bears an undeniable effect on human odour preferences.

Music is present in every known society but varies from place to place. What, if anything, is universal to music cognition? We measured a signature of mental representations of rhythm in 39 participant groups in 15 countries, spanning urban societies and Indigenous populations. Listeners reproduced random 'seed' rhythms; their reproductions were fed back as the stimulus (as in the game of 'telephone'), such that their biases (the prior) could be estimated from the distribution of reproductions. Every tested group showed a sparse prior with peaks at integer-ratio rhythms. However, the importance of different integer ratios varied across groups, often reflecting local musical practices. Our results suggest a common feature of music cognition: discrete rhythm 'categories' at small-integer ratios. These discrete representations plausibly stabilize musical systems in the face of cultural transmission but interact with culture-specific traditions to yield the diversity that is evident when mental representations are probed across many cultures., (© 2024. The Author(s).)