21,303 research outputs found
Of apples and oranges? The evolution of âmonogamyâ in non-human primates
Behavioral ecologists, evolutionary biologists, and anthropologists have been long fascinated by the existence of âmonogamyâ in the animal kingdom. Multiple studies have explored the factors underlying its evolution and maintenance, sometimes with contradicting and contentious conclusions. These studies have been plagued by a persistent use of fuzzy terminology that often leads to researchers comparing âapples with orangesâ (e.g., comparing a grouping pattern or social organization with a sexual or genetic mating system). In this review, we provide an overview of research on âmonogamyâ in mammals generally and primates in particular, and we discuss a number of problems that complicate comparative attempts to understand this issue. We first highlight why the muddled terminology has hindered our understanding of both a rare social organization and a rare mating system. Then, following a short overview of the main hypotheses explaining the evolution of pair-living and sexualmonogamy, we critically discuss various claims about the principal drivers of âmonogamyâ that have been made in several recent comparative studies.We stress the importance of using only high quality and comparable data. We then propose that a productive way to frame and dissect the different components of pair-living and sexual or genetic monogamy is by considering the behavioral and evolutionary implications of those components from the perspectives of all participants in a speciesâ social system. In particular, we highlight the importance of integrating the perspective of âfloaterâ individuals and considering their impacts on local operational sex ratios, competition, and variance in reproductive success across a population. We stress that pair-living need not imply a reduced importance of intrasexual mate competition, a situation that may have implications for the sexual selection potential that have not yet been fully explored. Finally, we note that there is no reason to assume that different taxa and lineages, even within the same radiation, should follow the same pathway to or share a unifying evolutionary explanation for âmonogamyâ. The study of the evolution of pair-living, sexual monogamy, and genetic monogamy remains a challenging and exciting area of research.Fieldwork related to the data discussed and presented here was supported through grants awarded to AD, EF-D, and their students by the Wenner-Gren Foundation, the L.S.B. Leakey Foundation, the J. William Fulbright Scholar Program, Primate conservation, Inc., Idea Wild, the National Geographic Society, as well by the New York Consortium in Evolutionary Primatology, New York University, the Zoological Society of San Diego, the University of Pennsylvania, the University of Texas at Austin, and Yale University, as well as through grants awarded to Eckhard W. Heyman and MH by the Deutsche Forschungsgesellschaft (HE 1870/10-1,2,3, HU1746-2/1). The Owl Monkey Project of Argentina was supported through the following grants to EFD: NSF-BCS-0621020, 1232349, 1503753 and 1848954; NSF-REU 0837921, 0924352 and 1026991; NSFRAPID-1219368; NIA- P30 AG012836-19, and NICHD R24 HD-044964-11
Structural stability of the two-fold singularity
At a two-fold singularity, the velocity vector of a flow switches discontinuously across a codimension one switching manifold, between two directions that both lie tangent to the manifold. Particularly intricate dynamics arises when the local flow curves toward the switching manifold from both sides, a case referred to as the Teixeira singularity. The flow locally performs two different actions: it winds around the singularity by crossing repeatedly through, and passes through the singularity by sliding along, the switching manifold. The case when the number of rotations around the singularity is infinite has been analyzed in detail. Here we study the case when the flow makes a finite, but previously unknown, number of rotations around the singularity between incidents of sliding. We show that the solution is remarkably simple: the maximum and minimum numbers of rotations made anywhere in the flow differ only by one and increase incrementally with a single parameter -the angular jump in the flow direction across the switching manifold at the singularity
Orcas and PCBs
The dramatic population decline which has been predicted to affect killer whales (Orcinus orca) on a global scale by the end of this century is of concern, with the levels of polychlorinated biphenyls (PCBs) in tissues from free-ranging orcas having been estimated to be among the highest in the animal kingdom (1).
As in other cetacean and non-cetacean âtop predatorsâ, in fact, lipophilic PCBs may heavily accumulate in killer whalesâ subcutaneous blubber, thereafter undergoing ad hoc âbiomagnificationâ processes. Since these bioaccumulation and biomagnification dynamics are shared by many other persistent environmental pollutants - either âclassicalâ (i.e. DDTs, dioxins, heavy metals, etc.) or âemergingâ (i.e. PBDEs, PFAS, micro- and nanoplastics, etc.) -, that almost unvariably form âmixturesâ to which aquatic organisms are chronically exposed via the marine food web(s) (2), one could wonder how the biological effects of PCBs may be effectively âdissectedâ from those of the other contaminants present in the aforementioned mixtures. Furthermore, the âendocrine disruptingâ and the additional pathogenic activities of PCBs on hostâs reproductive and immune functions are also known to be exerted by other organochlorine (OC) pollutants, the entry of which into exposed animalsâ cells is mediated by aryl hydrocarbon receptors (AHRs) (3). This implies that the susceptibility of a given species to PCBs and, more in general, to OC contaminants could âideallyâ result from the âsumâ of its trophic position and tissue expression level(s) of AHRs.
Alternatively, if not complementarily, such an increased tendency to accumulate high PCB tissue burdens might depend upon a metabolic capacity toward OC xenobiotics that is less efficient in orcas as compared to other odontocete cetacean species.
The prominent PCB immunotoxicity (3) has been also linked to an increased sensitivity toward infectious pathogens, as in the case of the dramatic Cetacean Morbillivirus (CeMV) epidemic which affected, between 1990 and 1992, the population of Western Mediterranean striped dolphins (Stenella coeruleoalba) (4). To the best of our knowledge, however, neither morbilliviral epidemics nor overt cases of morbilliviral infection have been hitherto reported in orcas, the susceptibility of which to CeMV is currently unknown. In this respect, should PCBs represent the major factor underlying the predicted killer whalesâ population decline (1), one could reasonably expect a prevalence of âopportunisticâ infections and/or neoplastic disease conditions (significantly) higher than in other cetacean and aquatic mammal species occupying a lower trophic level. Is this really the case? We are afraid that not enough, sufficiently reliable and robust data are available, thus far, to provide an affirmative or negative answer to the above query, considering also the âintrinsicâ limitation due to the fact that an undefined number of orcas, similarly to their cetacean âheterospecificsâ, will die in the open sea, with no possibility to perform a post mortem examination on them.
Finally, the dramatically increasing pollution of global oceans and seas by plastics, micro- and nanoplastics would also deserve special concern, given that micro- and nanoplastics may act as âattractors and concentratorsâ for many chemical pollutants (including PCBs) (5), coupled with their long distance transfer across marine waters, as it has been recently described following the catastrophic tsunami in March 2011 along the Eastern coast of Japan (6).
In conclusion, the herein dealt PCB-related alert (1), albeit of remarkable concern, appears to be influenced by a number of âenvironmentâ-dependent and âhostâ-related variables which should be carefully taken into account for an accurate evaluation of the effects of chronic PCB ingestion - and, more in general, exposure to OCs and other toxic pollutants - on killer whalesâ health and conservation
Release of anandamide from blood cells
Background: Endogenous ligands of cannabinoid receptors ( endocannabinoids), in particular anandamide ( arachidonylethanolamide), have been recognized as being of crucial importance in a variety of physiological functions. Plasma concentrations of anandamide have been measured in a number of investigations; however, discrepant data on "normal'' anandamide plasma concentrations were reported. Since this might be caused by pre-analytical variables, we investigated the impact of different sample handling conditions on measured plasma anandamide concentrations. Methods: Blood samples were taken from healthy volunteers in EDTA- or heparin-containing tubes; whole blood samples were kept at +4 degrees C, room temperature, or 37 degrees C, respectively, for up to 120 min before obtaining plasma by centrifugation. Plasma anandamide concentrations were measured by an isotope-dilution liquid chromatography tandem mass spectrometry ( LC-MS/MS) method. Results: A marked time- and temperature-dependent increase in plasma anandamide concentrations ex vivo was observed in both EDTA- and heparin-containing tubes. Mean anandamide concentrations approximately doubled when EDTA samples were kept at 4 degrees C for 60 min before centrifugation {[}immediately centrifuged, 1.3 mg/L ( SD 0.3 mg/L); 2.8 mg/L ( SD 0.5 mg/L) after storage for 60 min; n=12). After storage of heparinized whole-blood samples for 120 min at 37 degrees C, a mean plasma anandamide concentration of 11.9 mg/L ( SD 1.8 mg/L) was found. In cell-free plasma, no increase in anandamide concentrations was found. Conclusion: Anandamide is released from blood cells ex vivo at a very high rate; therefore, strictly standardized pre-analytical protocols have to be applied for plasma anandamide determination
The Gal4-Type Transcription Factor Pro1 Integrates Inputs from Two Different MAPK Cascades to Regulate Development in the Fungal Pathogen Fusarium oxysporum
Mitogen-activated protein kinase (MAPK) signaling pathways control fundamental aspects of growth and development in fungi. In the soil-inhabiting ascomycete Fusarium oxysporum, which causes vascular wilt disease in more than a hundred crops, the MAPKs Fmk1 and Mpk1 regulate an array of developmental and virulence-related processes. The downstream components mediating these disparate functions are largely unknown. Here we find that the GATA-type transcription factor Pro1 integrates signals from both MAPK pathways to control a subset of functions, including quorum sensing, hyphal fusion and chemotropism. By contrast, Pro1 is dispensable for other downstream processes such as invasive hyphal growth and virulence, or response to cell wall stress. We further show that regulation of Pro1 activity by these upstream pathways occurs at least in part at the level of transcription. Besides the MAPK pathways, upstream regulators of Pro1 transcription also include the Velvet regulatory complex, the signaling protein Soft (Fso1) and the transcription factor Ste12 which was previously shown to act downstream of Fmk1. Collectively, our results reveal a role of Pro1 in integrating the outputs from different signaling pathways of F. oxysporum thereby mediating key developmental decisions in this important fungal pathogen
Pollen and spores morphology from the Holocene of the IberĂĄ Wetlands in northeastern Argentina
IntroducciĂłn y objetivos: Los trabajos taxonĂłmicos de polen actual de la vegetaciĂłn de los esteros del IberĂĄ en el noreste de Argentina y otras ĂĄreas de la provincia de Corrientes se han llevaron a cabo mayoritariamente en la Ășltima dĂ©cada. Sin embargo, muy pocos de estos trabajos incluyen la ilustraciĂłn de los palinomorfos. El objetivo de esta contribuciĂłn es proporcionar el primer registro morfolĂłgico de palinomorfos de angiospermas, helechos, licofitas y briofitas de sedimentos del Holoceno de los Esteros del IberĂĄ. M&M: Se analizaron muestras de nĂșcleos obtenidos por medio de un muestreador tipo Livingston de seis lagos en sus partes central y mĂĄs profunda en el margen occidental de los Esteros del IberĂĄ. Resultados: Se describen e ilustran 55 tipos de palinomorfos: 46 tipos de polen corresponden a 27 familias de angiospermas y nueve tipos de esporas triletas a helechos, licofitas y briofitas. Se incluye informaciĂłn para diferenciar taxones locales (que forman parte de la vegetaciĂłn natural de los Esteros del IberĂĄ) y extra-locales (aquellos que no pertenecen al IberĂĄ) que lograron llegar a los depocentros provenientes de vegetaciĂłn regional mĂĄs lejana. Conclusiones: La identificaciĂłn de granos de polen y esporas hasta el nivel de especie mejora las reconstrucciones paleoambientales basadas sobre informaciĂłn ecolĂłgica y distribuciĂłn geogrĂĄfica mĂĄs precisas. Este trabajo amplĂa el conocimiento de la flora palinolĂłgica del noreste de Argentina y contribuirĂĄ a diferenciar la vegetaciĂłn local de la extra-local en futuras interpretaciones paleoecolĂłgicas y paleoambientales.Background and aims: Taxonomic works of the modern pollen grains from the vegetation of the IberĂĄ Wetlands from northeastern Argentina, and other areas of the Corrientes province, have mostly been carried out in last decade. However, very few of these taxonomic works include illustration of palynomorphs. The objective of this contribution is to provide the first morphological records of palynomorphs of angiosperms, ferns, lycophytes and bryophytes from sediments from the Holocene of the IberĂĄ Wetlands. M&M: Core samples obtained by mean of a Livingston-type sampler from six lakes in their central and deepest parts on the western margin of the IberĂĄ Wetlands were analyzed. Results: Fifty-five types of palynomorphs are described and illustrated: 46 pollen types correspond to 27 families of angiosperms and nine trilete spore-types to ferns, lycophytes and bryophytes. Information to differentiate local (species that form part of the natural vegetation of the IberĂĄ Wetlands) and extra-local taxa (those that do not belong to the IberĂĄ), that achieved to depocenters mostly by means of wind currents coming from farther regional vegetation, was included. Conclusions: Pollen grains and spores identifications up to species level enhances paleoenvironmental reconstructions based on more accurate ecologic information and geographical distribution. This work broadens the knowledge of the palynological flora of northeastern Argentina and it will contribute to differentiate the local vegetation from the extra-local in future paleocological and paleoenvironmental interpretations.Fil: Fernandez Pacella, Lionel Edgar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Centro de EcologĂa Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de EcologĂa Aplicada del Litoral; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de BiologĂa; ArgentinaFil: Di Pasquo Lartigue, Maria. Provincia de Entre RĂos. Centro de Investigaciones CientĂficas y Transferencia de TecnologĂa a la ProducciĂłn. Universidad AutĂłnoma de Entre RĂos. Centro de Investigaciones CientĂficas y Transferencia de TecnologĂa a la ProducciĂłn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Centro de Investigaciones CientĂficas y Transferencia de TecnologĂa a la ProducciĂłn; Argentin
Selective vulnerability of neurons to acute toxicity after proteasome inhibitor treatment: Implications for oxidative stress and insolubility of newly synthesized proteins
Maintaining protein homeostasis is vital to cell viability, with numerous studies demonstrating a role for proteasome inhibition occurring during the aging of a variety of tissues and, presumably, contributing to the disruption of cellular homeostasis during aging. In this study we sought to elucidate the differences between neurons and astrocytes in regard to basal levels of protein synthesis, proteasome-mediated protein degradation, and sensitivity to cytotoxicity after proteasome inhibitor treatment. In these studies we demonstrate that neurons have an increased vulnerability, compared to astrocyte cultures, to proteasome-inhibitor-induced cytotoxicity. No significant difference was observed between these two cell types in regard to the basal rates of protein synthesis, or basal rates of protein degradation, in the pool of short-lived proteins. After proteasome inhibitor treatment neuronal crude lysates were observed to undergo greater increases in the levels of ubiquitinated and oxidized proteins and selectively exhibited increased levels of newly synthesized proteins accumulating within the insoluble protein pool, compared to astrocytes. Together, these data suggest a role for increased oxidized proteins and sequestration of newly synthesized proteins in the insoluble protein pool, as potential mediators of the selective neurotoxicity after proteasome inhibitor treatment. The implications for neurons exhibiting increased sensitivity to acute proteasome inhibitor exposure, and the corresponding changes in protein homeostasis observed after proteasome inhibition, are discussed in the context of both aging and age-related disorders of the nervous system.Fil: Dasuri, Kalavathi. State University of Louisiana; Estados UnidosFil: Ebenezer, Philip J.. State University of Louisiana; Estados UnidosFil: Zhang, Le. State University of Louisiana; Estados UnidosFil: Fernandez Kim, Sun Ok. State University of Louisiana; Estados UnidosFil: Uranga, Romina Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto de Investigaciones BioquĂmicas de BahĂa Blanca. Universidad Nacional del Sur. Instituto de Investigaciones BioquĂmicas de BahĂa Blanca; ArgentinaFil: GavilĂĄn, Elena. State University of Louisiana; Estados UnidosFil: Di Blasio, Alessia. State University of Louisiana; Estados UnidosFil: Keller, Jeffrey N.. State University of Louisiana; Estados Unido
Transcriptomic identification of candidate genes involved in sunflower responses to chilling and salt stresses based on cDNA microarray analysis
<p>Abstract</p> <p>Background</p> <p>Considering that sunflower production is expanding to arid regions, tolerance to abiotic stresses as drought, low temperatures and salinity arises as one of the main constrains nowadays. Differential organ-specific sunflower ESTs (expressed sequence tags) were previously generated by a subtractive hybridization method that included a considerable number of putative abiotic stress associated sequences. The objective of this work is to analyze concerted gene expression profiles of organ-specific ESTs by fluorescence microarray assay, in response to high sodium chloride concentration and chilling treatments with the aim to identify and follow up candidate genes for early responses to abiotic stress in sunflower.</p> <p>Results</p> <p>Abiotic-related expressed genes were the target of this characterization through a gene expression analysis using an organ-specific cDNA fluorescence microarray approach in response to high salinity and low temperatures. The experiment included three independent replicates from leaf samples. We analyzed 317 unigenes previously isolated from differential organ-specific cDNA libraries from leaf, stem and flower at R1 and R4 developmental stage. A statistical analysis based on mean comparison by ANOVA and ordination by Principal Component Analysis allowed the detection of 80 candidate genes for either salinity and/or chilling stresses. Out of them, 50 genes were up or down regulated under both stresses, supporting common regulatory mechanisms and general responses to chilling and salinity. Interestingly 15 and 12 sequences were up regulated or down regulated specifically in one stress but not in the other, respectively. These genes are potentially involved in different regulatory mechanisms including transcription/translation/protein degradation/protein folding/ROS production or ROS-scavenging. Differential gene expression patterns were confirmed by qRT-PCR for 12.5% of the microarray candidate sequences.</p> <p>Conclusion</p> <p>Eighty genes isolated from organ-specific cDNA libraries were identified as candidate genes for sunflower early response to low temperatures and salinity. Microarray profiling of chilling and NaCl-treated sunflower leaves revealed dynamic changes in transcript abundance, including transcription factors, defense/stress related proteins, and effectors of homeostasis, all of which highlight the complexity of both stress responses. This study not only allowed the identification of common transcriptional changes to both stress conditions but also lead to the detection of stress-specific genes not previously reported in sunflower. This is the first organ-specific cDNA fluorescence microarray study addressing a simultaneous evaluation of concerted transcriptional changes in response to chilling and salinity stress in cultivated sunflower.</p
Assessing the impact of design factors on the performance of two miniature microbial fuel cells
Every day, wastewater treatment requires large amounts of electricity. Microbial Fuel Cells (MFCs) can convert wastewater treatment plants from net power consumers into energy neutral/positive systems by generating electricity from wastewaters. We investigate here the design factors that have major impacts on the performance of two miniature MFCs, and, consequently, of the resulting stack of MFCs. A versatile mathematical model is provided, which simulates the complex MFC system by integrating fluid dynamic principles with mass transport phenomena and (bio)electrochemical reactions. The model is used to support an in-depth study of the two MFCs, which differ for electrode spacing, anodic volume and fluid pattern within the anodic chamber, and to associate any difference in performance to design factors. Finally, system scale-up is demonstrated by generating stacks of the two MFCs. Thanks to the versatility of the model developed, this study becomes a guide for the effective development of future miniature MFCs
An impedimetric immunosensor for the selective detection of CD34+ T-cells in human serum
Chimeric antigen receptor T (CAR-T) cell therapy has led to a paradigm change in cancer treatment. To allow widespread use of this therapy, it is important to reduce the costs associated with cells manufacturing whilst ensuring a high-quality production. Online biosensors can help monitor in real time the effectiveness of engineering CAR-T cells, with the possibility to be integrated on the workflow without the need to extract samples for off line analysis that require specialised personnel and expensive analytical equipment. In this context, we present an innovative label-free impedimetric immunosensor for the detection of CD34 + T-cells in human serum. The sensor is based on screen-printed gold electrodes functionalised with anti-CD34 antibody, via a mixed self-assembled monolayer of 11-mercaptoundecanoic acid and 6-mercapto-1-hexanol, which recognizes the CD34 antigen expressed onto the T-cells surfaces. The immunosensor exhibits a high selectivity and a wide working range in human serum, both in Faradaic and non-Faradaic detection conditions, being respectively of 230 â 1.4 Ă 10 3 cell mL â1 and 50 â 1 Ă 10 5 cell mL â1. This result, along with performance validation both in batch and flow-through operations, demonstrates the applicability of the developed immunosensor for clinical use. </p
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