La Pampa Province Research Articles

Prevalence of high neonatal thyroid stimulating hormone levels as an indicator of iodine deficiency in the province of La Pampa: An epidemiological analysis.

Introduction. Iodine plays a key role in human metabolism, growth, and development. During pregnancy and childhood, the demand for this micronutrient increases notably. Increased neonatal thyroid stimulating hormone (nTSH) levels, defined as nTSH ≥ 5 mIU/L, are a marker of iodine deficiency in a population if its prevalence is higher than 3%. Objective. To establish the prevalence of nTSH ≥ 5 in La Pampa in the 2021-2022 period, analyze its correlation with different variables, and compare it with data from a historical cohort. Population and methods. Cross-sectional, descriptive-analytical study in a population of newborn infants born in the 5 health regions of the province of La Pampa in 2021 and 2022. Results. Of the 5778 assessed newborn infants, 9.6% had nTSH levels ≥ 5 mIU/L. It was reported that 70.4% of these measurements were done after the third day of life. No significant differences were observed in the frequency of high nTSH levels by year of birth, birth weight, or days until sample collection. A higher prevalence was observed among male infants (10.6% versus 8.5%; p = 0.007) and term infants (9.8% versus 6.6%; p = 0.02). The prevalence of high TSH levels was superior to that observed in the 2001-2002 cohort. Conclusions. The prevalence of high nTSH levels in La Pampa during 2021 and 2022 was 9.6%, suggesting the presence of mild iodine deficiency in the population of this province, higher that what had been reported 2 decades ago.

Dinomyid (Rodentia, Caviomorpha) diversity from the Late Miocene (Chasicoan Stage/Age) Cerro Azul Formation at the classical Arroyo Chasicó locality (Argentina)

ABSTRACT Dinomyidae is a South American group of caviomorph rodents with a single extant species (Dinomys branickii), but with a rich fossil record including medium-sized to giant species, which reached its peak diversity during the Late Miocene. The dinomyids from the Cerro Azul Formation (late Middle Miocene to Early Pliocene) have been studied in detail from localities in La Pampa Province, Argentina. In this contribution, dinomyids from Chasicoan Stage/Age (Late Miocene) levels of the Cerro Azul Formation at Arroyo Chasicó locality (Buenos Aires Province, Argentina) are revised, including previously published material and unpublished ones. We confirm the presence of Tetrastylus sp. Diaphoromys gamayensis, and define two new taxa, Bondesiomys chasiquensis gen. et sp. nov. and Gyriabrus sokka sp. nov. The diversity of dinomyids from the Cerro Azul Formation at Arroyo Chasicó is higher than other Chasicoan faunas at the same latitude, identified in localities of La Pampa Province, since in Cerro Patagua there are not Dinomyidae records and in Cerro la Bota Tetrastylus sp. and Dinomyidae indet. were the only recorded taxa.

Molecular based confirmation of puma meat sausages implicated in trichinellosis outbreaks in Argentina

Trichinellosis is a zoonotic disease caused by Trichinella, with the main source of infection being the consumption of pork and pork-derived products. However, it can also be acquired from eating the meat from wild animals targeted for sport hunting. The objectives of this study were: 1) to develop and implement a molecular method for the identification of Sus scrofa (pig and wild boar) and Puma concolor (Puma) meat in sausages eaten raw, which were linked to trichinellosis outbreaks occurring in Córdoba, Buenos Aires and La Pampa provinces, Argentina, in 2010, 2021, and 2022, respectively; and 2) to identify the Trichinella species present in the food. Specific primers were designed for PCR amplification and nucleotide sequencing of a region of the mitochondrial cytochrome b gene from both host species. Samples from the mentioned outbreaks were analysed, and the molecular identification of Trichinella spp. larvae was also performed. Results of the species identification system revealed that sausages from Córdoba and Buenos Aires had a mixed composition of pork and puma meat, while those from La Pampa contained puma meat only. Trichinella spiralis was implicated in all three outbreaks. The species identification system developed and implemented in this study revealed two host species of Trichinella related to human cases, and alerts about the risk of zoonotic transmission to humans through infected puma meat.

Atypical holocene ctenomyid rodent burrows related to eolian dune deposits from central Argentina

This contribution aims to interpret the producers and the paleoenvironmental context of Holocene rodent burrows (and associated ichnofossils) from the Late Pleistocene-Holocene Meaucó Formation, central La Pampa Province, Argentina. Fieldwork included a detailed sedimentary logging, a ground penetrating radar survey and documentation of the fossil burrow systems. The Meaucó Formation rest on erosive unconformity over the Upper Miocene-Lower Pliocene Cerro Azul Formation and display a vertical change from eolian dunes that become sparser up section (as imaged by ground penetrating radar) and were capped by a paleosol. The paleosol is covered by recent eolian dune and interdune deposits. The fossil rodent burrows occur up to 1.7 m below the paleosol and share several morphologic features with modern Ctenomyidae burrows, except the high slope of entrance and internal ramps, and the maximum depth of burrows. To explain these differences, it is proposed that the burrows were excavated by ctenomyids in ancient sloping surfaces of eolian dunes, which resulted in increased inclination and apparent maximum depth of the systems. This is an example of influence of environmental conditions on the architecture of rodent burrows, and can be of help when interpreting other similar fossil examples. The paleosol community associated with the fossil vertebrate burrows also included other organisms recorded by their trace fossils: horses (Hippipeda isp.), a scrubby vegetation (rhizoliths), coleoptera or spiders (Skolithos linearis), cicada nymphs (Feoichnus challa) and ants (Daimoniobarax isp.).

Paleoenvironmental reconstruction of a Neogene diatomite deposit from La Pampa Province (Argentina)

Diatomite deposits constitute siliceous biogenic sedimentary rocks primarily composed of diatoms. In Argentina, there is a scarcity of paleoenvironmental reconstructions for these deposits. This study focuses on the analysis of the diatom content in a Plio-Pleistocene diatomite from La Pampa Province. The aim is to identify diatom diversity and reconstruct the evolution of paleoenvironments. The studied section of 4.40 m is located at the CP site (38°08′40.5′’S; 67°09′23.2′’W, El Sauzal Formation). The profile is a laminated white diatomite with three levels of volcanic ash. Seven samples 50 cm-equidistant were extracted and oxidized with H2O2 for diatom analysis. 500 valves/slide were counted in order to calculate relative abundances. Diatom zones were defined using CONISS. The analysis revealed 72 morphospecies, with 28 of them exhibiting abundances > 4%. The diatom flora is predominantly composed of small fragilarioid diatoms accompanied by Discostella, Aulacoseira, Epithemia, Rhopalodia, and Cymbella species, indicating a lacustrine origin. At the base, a paleolake with a relatively alkaline pH, low nitrogen concentrations and high phosphates (volcanic ash) favored the growth of a diverse diatom community. Towards the top, the dominance of fragilarioids, the decrease in freshwater planktonic taxa and the presence of gypsum suggest a shallower environment with increased salinity during the drier periods of the Plio-Pleistocene.

Vertebrates from the Late Miocene of Salinas Grandes de Hidalgo (central Argentina). New faunal data: biochronological and paleoenvironmental considerations

ABSTRACT Salinas Grandes de Hidalgo (La Pampa Province) is a relevant locality of the Cerro Azul Formation in central Argentina because of its abundant and diverse vertebrate remains, including representatives of Reptilia, Aves and mostly Mammalia. Concerning previous records, the present faunal list adds one Argyrolagidae marsupial, one Ctenomyidae and two Caviidae rodents, as well as the first detailed analysis and description of glyptodonts from the Cerro Azul Formation in La Pampa Province. New geological information is added about the two fossiliferous outcrops included in Salinas Grandes de Hidalgo area. The classically studied outcrop located in the saline lake and the nearby one in the so-called ex-Autódromo, both herein correlated based on lithostratigraphy, particularly by the presence of paleosols in the intermediate section of the sedimentary succession. These sandy silts deposits in the base of the outcrops indicate the development of poorly confined flows and intervals of surface stabilisation by paedogenesis. We offer a biochronological interpretation based on a recently published U-Pb detrital zircons dating (5.9 ± 0.4 Ma) and the presence of significant taxa such as octodontoid rodents recovered from the dated levels and below it. From a paleoenvironmental viewpoint, we infer variations from woodlands to open environments.

First Report of Bothynus striatellus (Coleoptera: Melolonthidae) Damaging Lucerne Crops in Argentina.

We report for the first time that larvae of the genus Bothynus Hope (Coleoptera: Melolonthidae) caused economic damage to lucerne (Medicago sativa L., Fabaceae) crops in General Acha, province of La Pampa, Argentina. In two consecutive years (2021 and 2022), this insect infested 150ha of lucerne, causing seedling losses of 80ha. Based on soil sampling and laboratory insect rearing, the species was identified as Bothynus striatellus (Faimaire) (Coleoptera: Melolonthidae). Information is given here on the damage recorded in this forage crop, the density of the larvae observed at the time of damage assessment and the morphological characteristics of the third instar larvae reported in this crop in Argentina.

Vocal Repertoire of Chimango Caracaras in Rural and Urban Habitats

ABSTRACT Acoustic communication, such as bird song, is vital in animal ecology, facilitating reproduction, feeding, defense, and more. Variation in bird song may result from adaptation to environmental features such as anthropogenic noise. The vocal repertoire of raptors is essentially unstudied, particularly in urban environments. The aim of this work was to describe and quantify the acoustic repertoire of Chimango Caracaras (Milvago chimango) in rural and urban areas in La Pampa Province, Argentina. I recorded 26 1-min sound samples at each of four breeding colonies (one rural and three urban) during the austral reproductive season of 2021–2022. I recorded 241 vocalizations corresponding to nine clearly distinct call types. Two types of calls made up 50.6% and 19.5% of the vocalizations and seven others made up <10.0% each. Three call types had trills (fast repetitive notes). Average percentage of call types differed significantly between the two habitats (P < 0.01), with more trills produced in rural habitats. Average calling rate was 6.6 ± 5.1 calls/min at rural colonies and 10.7 ± 10.7 at urban colonies. The number of different call types produced was 2.1 ± 1.6 types/min at rural colonies and 2.7 ± 1.8 at urban colonies. The greater calling rate of Chimango Caracaras in urban areas may represent an attempt to improve signal effectiveness among the anthropogenic acoustic clutter.

Cyonasua zettii sp. nov. (Procyonidae, Mammalia) from the Late Miocene of Central Argentina and a review of the fossil record of Cerro Azul Formation

ABSTRACT A detailed taxonomic study of all known fossil specimens assigned to Procyonidae from sediments of Cerro Azul Formation (early Huayquerian Stage/Age, Late Miocene) outcroping at La Pampa and Buenos Aires provinces (Argentina) is presented here. Our study led us to propose a new species, Cyonasua zettii sp. nov. coming from La Pampa Province. In addition another six specimens studied, coming from La Pampa and Buenos Aires provinces, are assigned to Cyonasua longirostris and four specimens are assigned to Cyonasua sp. because its fragmentary nature prevents a determination at species level. The specimens described here are among the oldest records for the Order Carnivora (Mammalia) in South America.

Modeling and updating the occurrence of Aedes aegypti in its southern limit of distribution in South America

Aedes aegypti is the main vector of arboviruses in the world. This mosquito species is distributed from tropical to temperate regions. In Argentina, it has been reported in 20 out of 23 provinces and reaches its southernmost distribution in the world. Its distribution and persistence are affected by meteorological, demographic and environmental factors, such as temperature, precipitation, and population. The aim of this study was to update and model the occurrence of Aedes aegypti in its southern limit of distribution in Argentina. To this end, a total of 37 sites were inspected in La Pampa and Río Negro provinces. Generalized Linear Models were used to explain the occurrence of Aedes aegypti based on meteorological, environmental and demographic variables. Aedes aegypti was found in 11 cities of La Pampa province where it had not been previously reported, but was not found in any of the cities evaluated in Río Negro province. The averaged model explaining the occurrence of Aedes aegypti included the minimum temperature, precipitation and interactions between maximum temperature and precipitation as explanatory variables. Although precipitation was statistically significant, other factors such as minimum temperature are also important in modeling the occurrence of Aedes aegypti in its southernmost distribution limit.

Family group structure of the endangered Yellow Cardinal (Gubernatrix cristata)

The monogamous mating system, where a male and a female constitute the reproductive unit and share the parental care, predominates among bird reproductive strategies. However, there are also other mating systems with diverse parental care roles which may have implications for population breeding success and be relevant for their management and conservation. We evaluated the family group structure of the Yellow Cardinal ( Gubernatrix cristata) in La Pampa province of central Argentina. During the 2020–2021 breeding season we carried out 280 bird surveys to search for the presence of Yellow Cardinals. We registered 87 individuals (11 solitary individuals, 12 pairs, two males together, and 13 family groups). Most family groups corresponded to the typical monogamous structure, but two family groups (8%) were composed of two adult males, an adult female and at least a juvenile. We also explored 1646 Yellow Cardinal records at citizen science platforms and none of them included a family group with more than two adults. Even so, it would be feasible to release seized groups of two males together, to promote breeding success. Further studies are necessary to evaluate the causes of the presence of extra males and their incidence on the breeding performance of this globally endangered species. This may help to understand its natural history and for planning management and conservation actions.

New light on the late Middle Miocene–Early Pliocene representatives of Lagostomus (Chinchillidae, Rodentia) from Cerro Azul Formation, Argentina

Lagostominae (Rodentia, Caviomorpha, Chinchillidae) include a single living species, the plains vizcacha Lagostomus maximus, but representatives of this subfamily are registered since the Early Miocene. The oldest record of this genus was recently extended to the late Middle Miocene in one locality of center of La Pampa Province. Previously, from levels of the Late Miocene Cerro Azul Formation in Buenos Aires and La Pampa provinces, two species of Lagostomus were recognized based on specimens from two localities, L. telenkechanum from Arroyo Chasicó (Buenos Aires Province) and L. pretrichodactyla from Salinas Grandes de Hidalgo (La Pampa Province). In the present work, new materials from these two and other localities of the Cerro Azul Formation are analyzed. This study supports the presence of both species, which had coexisted in several of the analyzed assemblages. The studied sample includes several incomplete specimens and others interpreted as juvenile individuals, which can only be determined as Lagostomus sp. Also, a similar behavior to that of the extant L. maximus (i.e., gregarious populations with fossorial habits) is proposed to explain the different representation of Lagostomus in each assemblage. In Cerro Azul Formation the presence of representatives of Lagostomus is mainly linked with levels with paleosols and accumulations by predator activity. Finally, we conclude that this genus has less biostratigraphic value than previously thought, at least for central Argentina.

The synanthropic austral-most record of the species Loxosceles hirsuta and the formal record of Loxosceles laeta (Araneae: Sicariidae)

A formal record of the medically important species Loxosceles laeta (Nicolet, 1849) and new records of Loxosceles hirsuta Mello-Leitão, 1931 (Araneae: Sicariidae) are provided for La Pampa province, Argentina, comprising its southernmost record. The specimens of L. hirsuta in this work were found inhabiting human structures and were collected in different localities, between long time lapses, which suggests that L. hirsuta much like L. laeta is highly synanthropic and established in La Pampa.

Ancient parasite infections from the main Pampean-Patagonian cemetery of hunter-gatherer of prehistoric times: Archaeological site Chenque I (Parque Nacional Lihué Calel, La Pampa Province, Argentina)

Paleoparasitological studies of human sediment samples from prehistoric times of Argentina are scarce. The objective of the present study is to enhance the knowledge of parasitic infections affecting hunter-gatherer populations inhabiting the Pampean region of Argentina in prehistoric times. A total of 33 samples from 12 inhumation structures of archaeological site Chenque I, the unique cementery studied in Argentina until now from a paleoparasitological point of view, were studied. Chenque I constitute the greater repository of human archaeological remains of La Pampa province. Thirty-one samples came from human burials, and 2 samples from a dog retrieved in a burial, associated with a child. By humans, 11 samples correspond to males, 13 to females, and 7 to undifferentiated individuals. A total of 5 samples corresponds to control samples and were taken under the skull. Paleoparasitological examination revealed that 8 of the 33 sediment samples resulted positive for parasite remains applying the rehydration and spontaneous sedimentation technique with or without addition of HCl (10%). The pre-treatment of samples with HCl as a preliminary step allowed a greater recovery of parasitic remains compared to standard spontaneous sedimentation procedure. The most common parasite species found was Trichuris trichiura being probably one of the parasites that commonly affect human populations inhabiting the region. The low preservation evidenced by the parasite remains recovered indicate a taphonomic interference in the data of parasite assemblages, which probably produce a bias in the recovery of other parasite species that could infect these ancient populations. Proceed in the study of new human samples to improve the knowledge of parasitic infections affecting ancient populations inhabiting the studied region is necessary.

Strategic management of the agroindustrial network of first transformation in La Pampa, Argentina

ABSTRACT The objective of this work is to measure and analyze the management of resources and strategic capacities of the agroindustrial organizations of the first transformation of the province of La Pampa, Argentina. The strategic management of the network, measured in aggregate terms, can be classified as intermediate. The most positive aspects are maintaining the image of the company, the importance of price, and the strategic value that know-how has for businesses. As factors with performance to improve, there are the lack of conventions and agreements with scientific and technical organizations that promote innovation processes and the nonuse of a command board for the strategic and operational management of the business. The flour, dairy, and balanced food complexes were the ones that presented the best strategic management performance. The strategic management of first-transformation agroindustries is directly related to capacities (management training and seniority in the business) and resources (scale).

Burrow systems of modern subterranean rodents (Ctenomyidae): key neoichnologic features and recognition of fossil examples

This study is aimed to identify the distinctive ichnologic features of burrow systems of two ctenomyid species of extant solitary and subterranean rodents (Ctenomys azarae and C. talarum occidentalis) from La Pampa Province (Argentina). A total of 12 active burrows from different biogeographic provinces were cast with polyurethane foam, then excavated and the entire system was mapped. Ctenomyid burrow systems are shallow (average depth 0.30 m), branched, and subhorizontal with several plugged entrances, having a main tunnel and secondary ones arranged in a single level. Curved length, tortuosity, fractal dimension branching angles, and the scarcity or absence of chambers are similar in both species. The average horizontal diameter is 66 mm, the burrow cross-section is subcircular to vertical elliptical, and entrance ramps slope at an average of 22°. Surface ornamentation in the form of sets of three curved claw traces composing a chevron pattern is dominant. Ctenomys azarae is distinguished from C. talarum occidentalis by the presence of food caches and wider sets of claw traces. Ctenomyidae burrows are easily distinguished from those of Octodontidae and Caviidae using the relative diameter index. The outlined criteria are applied to identify fossil examples of Late Miocene-Holocene ctenomyid burrows.

The oldest Andean synorogenic fossiliferous deposits of the Miocene Cerro Azul Formation, central Argentina

Cerro Patagua is a locality with fossiliferous outcrops of the Cerro Azul Formation in La Pampa Province (central Argentina). First fossil remains were known in 1999 and assigned to the Chasicoan Stage/Age (Late Miocene, Tortonian) after the presence of the Octodontoidea rodent Chasichimys bonaerense. Later references to vertebrate remains were scarce and mostly limited to some mentioned taxa in broader faunal contexts. Now, we present a detailed taxonomic study of the entire mammal assemblage from Cerro Patagua, which evidences that most taxa are typical of the Chasicoan Stage/Age. A peculiar enterolith-like structure, recovered from loess levels, is also described, and several taphonomic aspects observed on fossils are related to their level of provenance. In addition, we offer stratigraphical interpretations of the Cerro Azul Formation and a geomorphological analysis of the Cerro Patagua area, and provide a detrital zircon dating of 12.3 ± 1.8 Ma. This result reflects the time interval 14.1–10.5 Ma, a temporal range that includes the Serravalian Stage (late Middle Miocene) and could indicate that the oldest synorogenic deposits could have begun to accumulate at the end of this stage. Even considering the minimum age of this interval (Tortonian Stage), this dating is the oldest obtained for the Cerro Azul Formation, compared with previous published data from Arroyo Chasicó locality (9.43–9.07 Ma). This assignment could explain that taxa from Cerro Patagua show affinities with Late Miocene mammal assemblages from central Argentina, as well as with older faunas from Patagonia and Bolivia.

Dónde, cuándo y cómo ocurren grandes incendios en la provincia de La Pampa, Argentina: Una caracterización basada en sensores remotos

Fire, as a catastrophic phenomenon, is devastating, dangerous and costly for a region. Despite its relevance, little is known about the spatial and temporal dynamics of this phenomenon in the province of La Pampa. The general objective of this work was to identify and characterize the fires, particularly the most extensive ones, that occurred in the province of La Pampa during the period July 2001-June 2017 (16 campaigns), based on the use of information provided by remote sensors. For this, information from MODIS Rapid Response heat sources, distributed by the FIRMS web system, was used. Combining information from spectral indices (NBR), precipitation data and vegetation types, the influence of predisposing factors on the occurrence of these events was studied It was observed that, in the analyzed period, between 21200 and 667500 ha/year were burned, with an average event size of 708 ha. However, in the last four seasons, an increase was recorded both in the total area burned and in the number of events ≥5 thousand ha. In the last campaign, in addition to registering the largest burned area (667500 ha), the largest number of events (10) ≥10 thousand ha (50% of the total events in this category) were observed. The total burned area in a campaign was positively related to the rainfall of the previous campaign (R2=0.76, P<0.001). The most affected vegetation was the xeric forest, followed to a lesser extent by the carob forests and the steppes and psamophilic scrubs. It is expected that the characterization of the spatial and temporal dynamics of fires using sensors will contribute to the design of prevention, early warning and control systems in the region.

Native Fauna of Tardigrades from Two Natural Areas of the Argentina Republic.

Understanding and preserving biodiversity in natural habitats is crucial due to their rapid degradation and destruction. The meiofauna of natural areas is less well known than the macroscopic life. Tardigrades are common in limno-terrestrial meiofauna and can indicate environmental conditions. In this study, we expand our understanding of the taxonomy and ecology of tardigrade communities in two natural reserves in Argentina by examining the environmental factors that can affect them and the species that could be used as indicators. In 2018, sampling occurred in the Parque Luro Provincial Reserve (province of La Pampa) and the Poligono A Municipal Ecological Reserve (province of Salta). Samples were taken from epiphytic communities that grow on the bark of trees. Various environmental and microhabitat factors were taken into account. In the province of La Pampa, there were 1326 specimens of five species, and in the province of Salta, there were 212 specimens of nine species. The tardigrade communities in Salta exhibited statistically higher diversity than those in La Pampa. Temperature and moisture affected the tardigrade community of Parque Luro Provincial Reserve, while the microhabitat thickness affected those of Poligono A Municipal Ecological Reserve. The species turnover shaped the community of Salta, while nesting shaped the community of La Pampa.

Combined isotope study of the Ordovician Cerro de los Viejos Granite, La Pampa province, Argentina. Its derivation from the autochthonous, early Mesoproterozoic southwesternmost border of the Río de la Plata craton

We have carried out the zircon U–Pb SHRIMP dating of the Cerro de los Viejos (CLV) Granite of southern La Pampa province, Argentina, which has yielded a concordia age of 468.0 ± 2.7 Ma, and determined the average Hf TDM model age of the dated zircon grains at 1491 Ma (Lower Mesoproterozoic; Calymmian), with an average epsilon Hf value of −3.13. Given the Ordovician (Darriwilian) crystallization age newly obtained for the CLV Granite, it becomes apparent that its previously known muscovite K–Ar Permian age of ca. 261 Ma would likely represent the age of the conspicuous shearing/mylonitization distinctive of this granitic body.Based on the new geochronologic and isotopic study of the CLV Granite, which also bears juvenile Rhyacian or “Transplatense” inheritance (aged at ca 2116 Ma, with average Hf TDM 2.4 Ga and average epsilon Hf value + 4.23) –an inheritance not known to occur in the neighbouring Patagonia or Pampia terranes–, as well as on comparisons with all the available geochronologic, isotopic, geophysical and geological data of the study region, in addition to broader tectonic considerations, we view the Ordovician CLV Granite as derived from the autochthonous, early Mesoproterozoic (Calymmian) southwesternmost portion of the Río de la Plata craton.The location of the CLV Granite would indicate that the peraluminous Ordovician magmatism of the southern La Pampa province, Argentina, straddles the Cambrian tectonic boundary between the Pampia terrane and the Río de la Plata craton.The CLV Granite would have been intruded in the immediate western continuation of the unexposed, E-W elongated upper crustal high/block recently identified by geophysical methods slightly to the east of the CLV Granite, the delineation of this block following the persistent sub-latitudinal structural fabric of the southern Río de la Plata craton, having also been reinforced by its probably late Middle Permian uplift coeval with the shearing of the CLV Granite.