Highland Valleys Research Articles

Variability of Puccinia striiformis f. sp. hordei, resistance and agronomic behavior of two-row barley germplasm

Barley crop production in Mexico in recent years has been affected by rust, of which yellow rust (YR) has regained its importance. This investigation aimed to identify the variability of YR and to evaluate the resistance level of seedlings and adult plants, the agronomic behavior of 15 advanced lines, and one control variety of two-row barley. During the 2021 spring-summer season, YR samples were collected from locations in the Highland Valleys of Central Mexico. Establishment of a field test in three locations allowed estimation of the agronomic behavior and resistance in adult plants; while evaluation of seedlings resistance was in a greenhouse. Nine YR isolations were identified, of which the most frequent (27%) was CMEX/21.9. Twelve lines expressed resistance in seedlings and adult plants. Alexia “s” is the candidate line with immunity to yellow rust. The results of resistance (field and greenhouse) and agronomic behavior allowed germplasm identification with outstanding characteristics. The release of varieties with genetic resistance to diseases contributes to the reduction of environmental deterioration.

Formative Exchange in the Andean Titicaca Basin: Isotopic Camelid Data and Lithic Sourcing: Evidence From the Taraco Peninsula, Bolivia

The Andean mountains have a mosaic distribution of resources, and no one place has everything a community requires for subsistence, social life and ritual. Therefore, from the very beginning of human habitation there is evidence for short-and long-distance movement and trade. Settled societies in the Andes most commonly used llama caravans that crisscrossed the mountains and highland valleys, although these are hard to identify. Here we present several data sets that inform about southern Lake Titicaca Formative movement of goods and caravans in the build-up to the caravan-driven polity of Middle Horizon Tiwanaku. Plant remains reveal the increasing tempo of goods movement. Olivine basalt results from XRF analyses clarify the extent of goods movement from their sources in the basin. Finally, strontium, carbon and oxygen isotope results from Formative camelid teeth inform us about the extent of long-and short-distance caravan movement emanating out of a shoreline ceremonial center.

Pathways to the interior: Human settlement in the Simbai-Kaironk Valleys of the Madang Province, Papua New Guinea

New Guinea has yielded some of the earliest evidence for a human presence in Sahul (Pleistocene Australia-New Guinea), with the north coast being one of the likely colonisation routes from Southeast Asia. Of the known pre-Last Glacial Maximum (≥30kya) archaeological sites from New Guinea, only a handful come from the Highlands. Navigable pathways linking the north coast to the central cordillera, specifically ‘grassland corridors’, may have facilitated settlement, yet little is known about human settlement of fringe montane valleys within these corridors. A survey and excavation program within the Simbai-Kaironk Valleys (2,000–1,600 m asl) on the northern montane fringe identified 51 sites across a 21 km corridor. Radiocarbon dating suggests a possible human presence from 31 ka, clear evidence for landscape use from 17 to 15 ka, and an increase in site density from the Mid-Holocene. Most sites were from open settings, with Holocene settlements positioned at elevations optimising access to montane forests, grasslands and lowland resources. We argue that the Simbai-Kaironk grassland corridor has facilitated access to the central Highland valleys since the Late Pleistocene. Shorter and more direct pathways, transecting the river valleys via prominent spurs rising above the lowlands – and their associated insect-borne diseases – are likely to have facilitated coastal-Highland movement throughout the Holocene.

ESTIMACIÓN DE EMISIÓN DE METANO ENTÉRICO EN SISTEMAS DE PRODUCCIÓN DE LECHE BOVINA EN PEQUEÑA ESCALA BAJO DIFERENTES ESTRATEGIAS DE ALIMENTACIÓN

<p><strong>Background: </strong>Small-scale dairy systems are a development option, and in Mexico they represent over 78% of dairy farms providing 37% of milk production. They are a source of employment and income in rural areas that enable dairy families to overcome poverty. However, ruminant production systems emit 17% of world methane, a greenhouse gas that affects climate change. Strategies must be devised to reduce the environmental footprint of dairy systems through increase productivity. <strong>Objective: </strong>The objective was to estimate the methane emission from enteric fermentation in small-scale dairy systems in the highland valleys of central Mexico with four feeding strategies. <strong>Methodology: </strong>Twenty four small-scale farms, with herds between 7 and 18 dairy cows participated in the study, which had implemented different feeding strategies that were assigned to the following groups: (CC) five farms that had a conventional management based on the cut-and-carry of temperate irrigated pastures, use of concentrates and straw, (CC+EM) six farms that use cut-and-carry of pastures plus maize silage in the dry season, (PCI) six farms that manage intensive continuous grazing of pastures, (PCI+EM) seven farms with continuous grazing of pastures, and use maize silage in the dry season. Farms were visited monthly during a whole year to record individual milk yields, milk composition and live weight of cows, to sample feeds for chemical analyses and record amounts of used feed. This information enabled to define a diet type per month, and dry matter and gross energy intakes were estimated subtracting the energy contribution of the supplements from total requirements. Methane emissions were estimated from a model derived by a global meta-analysis that includes variables of feed intake, diet composition, milk composition, and cow live-weight. A hierarchical experimental design was used where 288 records were subjected to analysis of variance to detect differences among the groups (alpha P≤0.05). <strong>Results</strong>: Farms that implemented grazing of pastures as a source of fresh quality herbage (PCI) in mean generated 10.5% less enteric methane and 13.9% les intensity of emission (P<0.05) compared with those that incorporated cut and carry or implemented corn silage for the dry season. <strong>Implications:</strong> Results show the potential of small-scale dairy systems to reduce their methane emissions and intensity of emissions by implementing grazing of temperate irrigated pastures. <strong>Conclusions:</strong> The implementation of fresh quality herbage through continuous grazing of temperate irrigated pastures with the use of moderate supplementation without incorporation of corn silage is a viable methane mitigation strategy in small-scale dairy systems in the highlands of Mexico.</p>

The Cenozoic deposits of the ancient landscapes of Quadrilátero Ferrífero highlands, Southeastern Brazil: Sedimentation, pedogenesis and landscape evolution

The Quadrilátero Ferrífero (QF), Southeastern Brazil, is a very important tropical highland region in the world’s geological context for its large and diverse Archean and Proterozoic rocks with great reserves of gold, iron, manganese, aluminum and industrial rocks, on a apparently stable geological structure. There, Cenozoic deposits perched on highland valleys show unclear genetic relationships with the underlying bedrock, with no apparent regional correlation. We studied five representative Cenozoic deposits (BR356, Água Limpa, Padre Domingos, Pau Branco and Casa de Pedra) on the highlands of the Serra da Moeda syncline, Western QF, to answer the question of their sedimentological origin, and investigate their pedological evolution. Field sampling was complemented by macromorphological, mineralogical and micromorphological analysis supported by X-ray diffraction (XRD), differential thermal analysis (DTA), infrared analysis (IR), scanning electron microscopy (SEM), micropobre and transmission electron microscopy (TEM). The evolution of these isolated highland deposits comprises a deep-weathered source area, a tectonic activity, besides sedimentological and pedological processes, during and after the deposition. The deposits overlie deep saprolites of Precambrian rocks (Piracicaba and Itabira Groups), representing unconformable contact. The onset of the deposition was marked by torrential, coarse colluvial and large blocks landslides into the small basins generated by reactivating tectonic events during the Oligocene, producing local grabens. These tectonic basins were filled by cohesive debris and mudflow from the adjacent and previously laterized cover, developed under the hot and humid climate in the Eocene. The cover reveals an upside-down lateritic profile where morphology and kaolinite crystal properties (values of size of coherent scattering thickness ranging from 135 Å to 162 Å) in the bottom is related to the pedolith horizons of the former lateritic cover. Later, due to climate changes (during and after the Miocene), renewed weathering on these pre-weathered sediments occurred, characterized by alternating ferruginization and Fe-losses, with the superimposed generation of new pedogenic features such as nodules, ferruginous duricrusts and mottling (redox features). In addition to demonstrating that the Brazilian platform was not stable during the Cenozoic, these deposits reveal the role of polygenetic tropical pedological processes in their formation and transformation.

A review on research advances in ethnobotany and pharmacognosy of some medicinal plants

Since remote times herbal medicines are the primary sources of health cure of the rural people throughout the world. The knowledge on the medicinal plants is inherited from generation to generation in the family of herbal doctors. Although significant advances have been made in modern allopathic medicine, medicinal plants are extensively used even in the cities specially in Mexico and Medicinal plants are largely sold both in the rural and urban markets. One of the reasons is due to the no-availability of good doctors in the rural areas, high confidence of the rural people and high cost of the allopathic medicine. In Mexico although several hundreds of medicinal plants are known to alleviate various types of diseases, still many species are not yet explored from the rural areas. There is a great necessity to formulate a systematic research starting from ethnobotany, botany and pharmacognosy including histochemistry and finally phytochemistry. With these objectives, some advances have been made on some medicinal plant species both in north-east and high land valleys of Mexico obtained mainly through research projects and thesis projects both in the bachelor and post-graduate levels. In the first step in the north-east of Mexico, through several visits in the rural areas and herbal shops and interviews a list of common species has been made, collected and preserved in the herbarium sheets. Then on the basis of a very careful analysis, most important and common medicinal species was selected for the studies on pharmacognosy, histochemistry and pharmacological tests on animals. An analysis of pharmacognosy showed the presence of distinct morphological, anatomical and histochemical characters in each species which can distinguish among species. In the high land valleys in Puebla and Tlaxcala, a more systematic interdisciplinary research has been undertaken including ethnobotany, pharmacognosy and some preliminary phytochemistry of several medicinal plant species. The efficacy of some medicinal plant species used by the herbal specialists has also been confirmed by a specialist of high recognition in the city. The species studied are: Artemisia absinthium, Chamaemelum nobile, Chenopodium ambrosoides, Ocimum sanctum, Origanum vulgare, Origanum majorana, Lavandula angostifolia, Marrubium vulgare, Mentha spicata, Rosmarinus officinalis, Salvia officinalis, Semipervivum tectorum, Thymus vulgaris and Turnera vulgaris. The medicinal herbs contained several secondary metabolites, among which alkaloids, saponins, triterpenes, flavonoids, cyanogenic and cardiotonic glucosides, the presence, absence and intensity of which vary among species. Although sufficient researches have been concentrated mostly on the phytochemistry in Mexico, no systematic research has been undertaken as planned. A catalogue of some medicinal plants has been made and some medicinal plant species are grown in the green house. Finally, a systematic research plant has been suggested on the medicinal plants. An interdisciplinary research including herbal specialists, botanists, agronomists and chemists is in progress.

Impact of Temperature and Relative Humidity on PMD in Directly Buried Optical Fibre Cables in Semi-Arid and Tropical Highlands in Kenya

The telecommunication industry has implemented fibre deployment guidelines that reliably safeguard cable health during installation in the field. While installed fibre cables remain buried in the field, temperature and moisture in the locality subject them to mechanical expansions and corrosion. Directly buried fibre cables experience accelerated degradation that results from exposure to harsh environments. This increases pulse spreading and overlaps, with a mean time duration, known as Differential Group Delay (DGD), on the signal, as it propagates along the cable. DGD is stochastic; thus, Mean DGD is determined and presented as Polarization Mode Dispersion (PMD). This work undertook a real life assessment of how fluctuations in temperature and relative humidity influence PMD in directly buried fibre optical links, in a case study that focused on the fibre cable network owned by Liquid Telecom Kenya. The network spans across two key climatic ecosystems, namely, rift valley highlands and northern lowlands. The analysis revealed that fibre cables experience higher PMD in semi-arid areas by a factor of 2.6, compared to highland areas.

Hydraulic Chiefdoms in the Eastern Andean Highlands of Colombia

The natural and cultural heritage of the Valley of Leiva in the Eastern Colombian Andes is closely tied to the Colonial town of Villa de Leyva. The popular tourist destination with rapid economic development and agricultural expansion contrasts sharply with an environment of limited water resources and landscape erosion. The recent discovery of Prehispanic hydraulic systems underscore ancient responses to water shortages conditioned by climate change. In an environment where effective rainfall and erosion are problematic, irrigation was vital to human settlement in this semi-arid highland valley. A chiefly elite responded to unpredictable precipitation by engineering a hydraulic landscape sanctioned by religious cosmology and the monolithic observatory at El Infiernito, the Stonehenge of Colombia. Early Colonial water works, however, transformed Villa de Leyva into a wheat breadbasket, though climatic downturns and poor management strategies contributed to an early 17th century crash in wheat production. Today, housing construction, intensive agriculture, and environmental instability combine to recreate conditions for acute water shortages. The heritage of a relatively dry valley with a long history of hydraulic chiefdoms, of which modern planners seem unaware, raises concerns for conservation and vulnerability to climate extremes and the need for understanding the prehistoric context and the magnitude of water availability today. This paper examines human ecodynamic factors related to the legacy of Muisca chiefdoms in the Leiva Valley and relevant issues of heritage in an Andean region undergoing rapid socio-economic change.

Application of the climate analogue concept in assessing the probable physiological and haematological responses of Friesian cattle to changing and variable climate in the Kenyan Highlands

Friesian cattle are considered the most sensitive to climate change-induced thermal stress and remain the major dairy breed in Kenya. This study applied the climate analogue concept to predict probable physiological and haematological responses of Friesian cattle in the 2050s to understand their adaptability to a changing and variable climate. Njoro in the Kenya Rift Valley Highlands was used as the reference site and its 2050s climate analogue site was identified in Shawa, based on criteria of a similarity index of 0.8–0.9. Results suggest that Njoro in the 2050s will likely experience increasing temperatures, but changes in rainfall are uncertain. The increasing temperatures will probably be accompanied by mild thermal stress for Friesian cattle during the dry seasons or drought. The thermal humidity index differed between times of day, but not between the analogue sites. Except for rectal temperatures, the physiological and haematological responses differed between the analogue sites, but were within the normal ranges. It is concluded that Friesian cattle in Njoro in the 2050s will probably experience mild thermal stress in the afternoons during the dry seasons, expressed by slight increases in physiological and haematological responses, but will probably remain within the normal margins.Keywords: Dairy cattle, haematimetric, Njoro, Rongai, thermal humidity index

Andean Waterways: Resource Politics in Highland Peru by Mattias Borg Rasmussen

Reviewed by: Andean Waterways: Resource Politics in Highland Peru by Mattias Borg Rasmussen Kimberly Munro Mattias Borg Rasmussen Andean Waterways: Resource Politics in Highland Peru Washington: Univ. of Washington Press, 2015. xxv + 2017 pp. Maps, illus., notes, references. $18.14 paper (ISBN 9780295994932); $90.00 hardcover (ISBN 0295994819); $23.99 electronic (ISBN 0295994932). Mattias Borg Rasmussen's work in Andean Waterways explores how a changing climate is enmeshed in all aspects of everyday life. Rasmussen's ethnography takes place in the Department of Ancash, Peru, in the town of Recuay and its surrounding communities and hamlets. Situated in the Callejón de Huaylas, a highland valley flanked by the mountains of the Cordillera Negra to the west, and stunning views of the Cordillera Blanca to the east, Andean Waterways is an ethnography structured around the question of how a changing climate is affecting the Santa River and its tributaries. Rasmussen, based at the University of Copenhagen, utilizes water to frame the complex relationship between Andean peasant communities and municipal and state governments. Water dynamics, specifically, are not part of the same infrastructure at the local level that they are at the state level, having been formed from centuries of water control at the local level in agro-pastoral Andean communities. Receding glaciers and the transformation of the Santa River's "beautiful flow" to a now unpredictable "devil river" (p. 32), further complicates matters. Andean Waterways highlights the conversations, local politics, and actions taken at the human scale within communities on the forefront of this global problem. The theme of "flow" is examined in both a physical and metaphorical sense in Andean Waterways. Rasmussen focuses on five separate [End Page 246] tributaries and canals, following the courses these channels take through different communities and farmlands. Specifically, Rasmussen discusses the flow and interconnectedness of water, and "the configuration of actors, histories, territories, and environmental conditions that enable or inhibit the water" (p. 21). Because basic infrastructure provided by the national government is often lacking in these rural communities, towns like Recuay are "dominated by local power figures … acting in opposition to the Lima-centered national administration. Therefore, the interests of local governments do not always coincide with national interests" (p. 164). These networks of power relations are presented after an insightful discussion on the meaning of place, space, and structuring landscapes. In the Andes, "Water is Life" (a phrase repeated throughout the ethnography), and Lake Conococha, the source of the Santa River, is considered "The heart of Ancash" (p. 157). Andean Waterways presents interviews with community members and detailed accounts of community meetings, government documents, and local protests, all structured around the control of water. Whether it is navigating the politics of constructing new canals through communal plots of land and privately owned chacras, or the protesting of a mine being constructed near Lake Conococha, Rasmussen's work delves into a world of water access, control, and distribution, where "killing the lake is like killing the people" (p. 157). Rasmussen's book complements the work of geographers and historians on mining (Bebbington and Bury 2009), the catastrophic effects of glacial melt (Carey 2010), and social repercussions of climate change (Bury et al. 2013) in the Ancash region, with implications for the central Andes more broadly. Using the classic anthropological approach of ethnographic inquiry of the small Andean community, Rasmussen echoes and amplifies the valuable research of Mark Carey (a collaborator of Rasmussen's; see Carey, et al. 2017). The unique contribution of Andean Waterways lies in its first-hand account of the impact global climate change on the language and livelihood of peasant communities. The local people are at center stage, and Rasmussen eschews scientific jargon in favor of personal accounts of the everyday machinations required to cope with the changing landscape. Rasmussen's ethnography also contributes to conversations on the theme of abandonment, in a multi-scalar way. First, these rural peasant communities have expressed a feeling of abandonment by the state and NGO actors. These rural communities feel this state abandonment not just in terms of water systems, but also in a lack of maintenance and investment in roadways, health services, schools, and other vital community infrastructure. Abandonment is...

Occurrence of selected elements (Ti, Sr, Ba, V, Ga, Sn, Tl, and Sb) in deposited dust and human hair samples: implications for human health in Pakistan.

The current study determined, for the first time, the levels of titanium (Ti), strontium (Sr), barium (Ba), vanadium (V), gallium (Ga), tin (Sn), thallium (Tl), and antinomy (Sb), in deposited dust, and human hair collected from general population of different geographical areas of Pakistan. All the samples were prepared by microwave digestion and measured by ICP-MS. The results showed that on deposited dust samples, the detected elements followed the descending trend as: Ti>Sr>Ba>V>Ga>Sn>Tl>Sb similar to the upper continental crust. The deposited dust samples from low elevation areas exhibited highest levels of all studied elements (except antimony which was higher in soil samples from mountainous areas), followed by rive plains, mountainous areas, and highland valleys. In contrast, on human hair samples, the elements followed the descending trend as: Sr>Ba>Ti>Ga>V>Sn>Sb>Tl respectively. Ba, Ga, and V concentrations were higher in soil samples from lower elevation Indus plain, and Sr, Tl, Sb, and Ti were higher in samples from mountainous areas. The bioaccumulation trend of all studied elements was in descending order as follows: Sb, Ga, Sn, Ba, Sr, Ti, V, Tl, respectively. Principal component analysis (PCA) and correlation matrix evidenced both geological influences and anthropogenic activities as potential sources of these studied elements. On the other hand, the risk estimation (HI>1) concluded that population were at higher health risk (non-carcinogenic) for Ga and Ti. All other studied rare elements were within safe limit for humans from all zones.

Grain Yield and Stability of White Early Maize Hybrids in the Highland Valleys of Mexico

There is great interest in Mexico in reducing imports of grain and becoming self‐sufficient in cereal production. Identifying high‐yielding and stable maize (Zea mays L.) hybrids from different research institutions could contribute to increasing maize production in the highlands of Mexico. In this study, 16 early white maize hybrids were evaluated at 37 highland sites in several Mexican states with the objective of identifying high‐yielding and stable hybrids, as well as high‐yielding sites. Using the site regression model, it was possible to identify some outstanding hybrids (CHLHW09035, CHLHW02517, and HIBRIDO 2010) with acceptable grain yield production that were also stable across most of the 37 sites. Hybrids ST‐010 and ASPROS‐823 were less stable but produced acceptable yields. Sites with higher stability included Site 26 (Amealco, Queretaro), Site 7 (Epitacio Huerta, Michoacan), Site 37 (Tlachaloya, State of Mexico), Site 34 (Ciudad Hidalgo, Michoacan), and Site 29 (Metepec, State of Mexico). Other sites with satisfactory stability included Site 20 (Jilotepec, State of Mexico), Site 5 (Quecholac, Puebla), Site 6 (Huejotzingo, Puebla), Site 13 (Ajacuba, Hidalgo), and Site 19 (Santo Domingo, Oaxaca).

Interaction and Cultural Change in the Peruvian Central Highland Valley of Ayacucho

Human societies are not isolated islands; instead, they are part of a complex web that links them with far away communities who are not only culturally different, but also inhabit different environmental settings. In the distant past, cultural interaction enabled the exposure to previously unknown customs and the flow of ideas, in addition to access to foreign exotic goods and the establishment of new kinship ties. Contact with more complex societies and significant locations likely also resulted in the enhancement of status and prestige of specific individuals. Archaeological evidence coming from the Peruvian central highland valley of Ayacucho indicates that as early as the late Early Intermediate Period (ca. 450–550 C.E.), the ancient inhabitants of the region were already part of a large network that linked them with their neighbours of the eastern tropical rain forest region as well with the inhabitants of the dry Pacific coast region. Interaction among members of different cultures precipitated not only the acceptance of previously unknown products and associated cultural practices, such as the use of coca leaves, but also significant cultural transformation in the Ayacucho Valley that ultimately culminated in the establishment of the Wari State.

Wild food plants and fungi used in the mycophilous Tibetan community of Zhagana (Tewo County, Gansu, China).

BackgroundThe aim of the study was to investigate knowledge and use of wild food plants and fungi in a highland valley in the Gannan Tibetan Autonomous Region on the north-eastern edges of the Tibetan Plateau.MethodsField research was carried out in four neighbouring villages in a mountain valley of the Diebu (Tewo) county, surrounded by spruce forests. The study consisted of 30 interviews with single informants, or group interviews (altogether 63 informants). Apart from collecting voucher specimens, we also identified fungi using DNA barcoding.ResultsWe recorded the use of 54 species of vascular plants. We also recorded the use of 22 mushroom taxa, which made up the largest category of wild foods. Fruits formed the largest category of food plants, with 21 species, larger than the wild greens category, which consisted of 20 species eaten after boiling or frying and 7 as raw snacks. We also recorded the alimentary use of 10 species of edible flowers and 3 species with underground edible organs. On average, 20.8 edible taxa were listed per interview (median – 21). The most listed category of wild foods was green vegetables (mean – 7.5 species, median – 8 species), but fruits and mushrooms were listed nearly as frequently (mean – 6.3, median – 6 and mean – 5.8, − median 6 respectively). Other category lists were very short, e.g., flowers (mean – 1.3, median – 1) and underground edible parts (mean – 0.7, median – 1).Wild vegetables are usually boiled and/or fried and served as side-dishes, or their green parts are eaten as snacks during mountain treks (e.g., peeled rhubarb shoots). Wild fruits are mainly collected by children and eaten raw, they are not stored for further use. The most widely used wild staple foods are Potetilla anserina roots, an important ceremonial food served on such occasions as New Year or at funerals. They are boiled and served with sugar and butter. The most important famine plants remembered by people are the aerial bulbils of Persicaria vivipara. Flowers are used as children’s snacks – their nectar is sucked.ConclusionsThe number of wild taxa eaten in the studied valley is similar to that of other Tibetan areas. The structure of wild food plant taxa is also very typical for Tibetan speaking areas (e.g., the use of rhubarb shoots, Potentilla anserina, Persicaria vivipara). The studied community show a high level of mycophilia.

Early Prehistoric Maize in Northern Highland Ecuador

The discovery of the fully developed Formative sites of Cotocallao (ca. 3750-2350 cal. B.P.) in the Quito Basin and La Chimba (ca. 2650-1700 cal. B.P.) in the northern highlands of Ecuador has raised questions about their cultural antecedents, which have not been resolved despite decades of archaeological work in the region. Paleoenvironmental coring investigations were conducted at Lake San Pablo in northern highland Ecuador to determine the date for the onset of prehistoric maize farming in the temperate highland valleys of this region. The investigations included analysis of lake sediments for pollen, phytoliths, diatoms, and tephra. Maize pollen was identified as early as 4900 cal. B.P., while maize phytoliths dated even earlier, to 6200 or 6600 cal. B.P. These results demonstrate a long history of maize farming in valleys around Lake San Pablo, but in the context of a punctuated record of major and minor volcanic eruptions. It is concluded that early horticultural sites predating Cotocallao and La Chimba must exist, but to find such sites, archaeologists will have to locate and study deeply buried A-horizon soils.

Ten years (2004-2014) of Chagas disease surveillance and vector control in Ecuador: successes and challenges.

To describe the current situation of Chagas disease in Ecuador and to evaluate the impact of vector control for the period 2004-2014. Since 2004, the Ministry of Public Health has formalized activities for the surveillance and control of Chagas disease and we analyzed here available records. More than 200 000 houses were surveyed, and 2.6% were found to be infested (95% CI: 2.6-2.7), and more than 51 000 houses were sprayed with residual insecticide, with important yearly variations. A total of 915 cases of T. cruzi infection were registered. The Amazon region is emerging as a high priority area, where nearly half of T. cruzi infection cases originate. The costal region and the southern highland valleys remain important high-risk area. Vector control efforts over the past 10 years have been effective in the coastal region, where T. dimidiata predominates, and resulted in important reductions in house infestation indices in many areas, even reaching negligible levels in some parishes. Vector efforts need to be sustained and expanded for the elimination of T. dimidiata to be feasible. Novel vector control interventions need to be designed to reduce intrusion by several triatomine species present in the Amazon region and southern Ecuador. Strong political commitment is needed to sustain current achievements and improve the national coverage of these programmes.

A process‐based investigation into the impact of the Congo basin deforestation on surface climate

AbstractThe sensitivity of climate to the loss of the Congo basin rainforest through changes in land cover properties is examined using a regional climate model. The complete removal of the Congo basin rainforest results in a dipole rainfall anomaly pattern, characterized by a decrease (∼−42%) in rainfall over the western Congo and an increase (∼10%) in the basin's eastern part. Three further experiments systematically examine the individual response to the changes in albedo, surface roughness, and evapotranspiration efficiency that accompany deforestation. The increased albedo (∼) caused by the Congo basin rainforest clearance results in cooler and drier climate conditions over the entire basin. The drying is accompanied with a reduction in available surface energy. Reducing evapotranspiration efficiency or roughness length produces similar positive air temperature anomaly patterns. The decreased evapotranspiration efficiency leads to a dipole response in rainfall, similar to that resulting from a reduced surface roughness following Congo basin rainforest clearance. This precipitation anomaly pattern is strongly linked to the change in low‐level water vapor transport, the influence of the Rift valley highlands, and the spatial pattern of water recycling activity. The climate responds linearly to the separate albedo, surface roughness, and evapotranspiration efficiency changes, which can be summed to produce a close approximation to the impact of the full deforestation experiment. It is suggested that the widely contrasting climate responses to deforestation in the literature could be partly due to the relative magnitude of change of the radiative and nonradiative parameterizations in their respective land surface schemes.

Genetic variation of the granule-bound starch synthase I (GBSSI) genes in waxy and non-waxy accessions of Chenopodium berlandieri ssp. nuttalliae from Central Mexico

Huauzontle (Chenopodium berlandieri ssp. nuttalliae) is a locally important vegetable crop native to the highland valleys of Central Mexico and a potential source of genes for improving its Andean sister crop, quinoa (Chenopodium quinoa). A previous work involving two huauzontle lines identified one waxy genotype that lacked amylose due to mutations in granule-bound starch synthase I (GBSSI), major amylose-synthesis genes with two constituent subgenomes, A and B. We conducted this study to determine the extent of waxy genotypes and cryptic GBSSI mutations in 11 huauzontle accessions or landrace populations extending from Puebla in the southeast to Jalisco in the northwest. This represents one of the first published studies of genetic variation in C. berlandieri ssp. nuttalliae. Accessions were phenotyped for opaque versus translucent seed morphology and their seed starches were stained with Lugol's Stain. In addition, complete or partial GBSSI genes from their A and B genomes were polymerase chain reaction (PCR)-amplified, cloned and sequenced. Seven accessions were either wholly or partially non-waxy while six were either entirely or partially waxy. All waxy accessions carried the same putatively null alleles, designated gbssIa-tp (A-genome) and gbssIb-del (B-genome). The identification of publicly available genotypes carrying gbssIa-tp and their potential use in breeding waxy grain quinoa is discussed.

A Mosaic of Adaptation: The Archaeological Record for Mesoamerica’s Archaic Period

Mesoamerica’s Archaic period lasted for seven millennia beginning at the end of the Younger Dryas (~8000 cal. BC). The end of this period was uneven, with the earliest ceramic-using villagers documented at 1900 cal. BC, but not until the end of the second millennium BC in the Maya lowlands. Food production progressively increased in Mesoamerica between 8000 and 1000 cal. BC but did not significantly alter a mixed foraging–horticultural adaptation. During the third and fourth millennia BC, sedentism increased around permanent sources of water with dependable aquatic resources, such as the lakes in the Basin of Mexico and the estuaries of the Gulf coast and the Soconusco region on the Pacific coast. A mosaic of different adaptations was created, with more mobile peoples inhabiting the dry highland valleys of Mexico and Guatemala and much of the Maya lowlands. I argue that the ultimate cause of both the beginning and the end of the Archaic period was a return to wet, warm, and more stable environmental conditions after the Younger Dryas and the three-century-long 2200 cal. BC “event.” Ultimate climatic causes, however, provide only a limited understanding of the past, whereas proximate causes provide a more complete picture of where, when, and how food production, sedentism, and ceramic use developed. The archaeological record provides the complex and regionally varied evidence to reconstruct the proximate processes that saw Mesoamerican peoples transform from small groups of dispersed foragers to sedentary food producers who laid the foundation on which later Mesoamerican civilizations were built.

Global modelling of the early martian climate under a denser CO2 atmosphere: Water cycle and ice evolution

We discuss 3D global simulations of the early martian climate that we have performed assuming a faint young Sun and denser CO2 atmosphere. We include a self-consistent representation of the water cycle, with atmosphere–surface interactions, atmospheric transport, and the radiative effects of CO2 and H2O gas and clouds taken into account. We find that for atmospheric pressures greater than a fraction of a bar, the adiabatic cooling effect causes temperatures in the southern highland valley network regions to fall significantly below the global average. Long-term climate evolution simulations indicate that in these circumstances, water ice is transported to the highlands from low-lying regions for a wide range of orbital obliquities, regardless of the extent of the Tharsis bulge. In addition, an extended water ice cap forms on the southern pole, approximately corresponding to the location of the Noachian/Hesperian era Dorsa Argentea Formation. Even for a multiple-bar CO2 atmosphere, conditions are too cold to allow long-term surface liquid water. Limited melting occurs on warm summer days in some locations, but only for surface albedo and thermal inertia conditions that may be unrealistic for water ice. Nonetheless, meteorite impacts and volcanism could potentially cause intense episodic melting under such conditions. Because ice migration to higher altitudes is a robust mechanism for recharging highland water sources after such events, we suggest that this globally sub-zero, ‘icy highlands’ scenario for the late Noachian climate may be sufficient to explain most of the fluvial geology without the need to invoke additional long-term warming mechanisms or an early warm, wet Mars.