Search

Abstract To identify potential factors influencing age-related cognitive decline and disease, we created MindCrowd. MindCrowd is a cross-sectional web-based assessment of simple visual (sv) reaction time (RT) and paired-associate learning (PAL). svRT and PAL results were combined with 22 survey questions. Analysis of svRT revealed education and stroke as potential modifiers of changes in processing speed and memory from younger to older ages (n total = 75,666, n women = 47,700, n men = 27,966; ages 18–85 years old, mean (M)Age = 46.54, standard deviation (SD) Age = 18.40). To complement this work, we evaluated complex visual recognition reaction time (cvrRT) in the UK Biobank (n total = 158,249 n women = 89,333 n men = 68,916; ages 40–70 years old, M Age = 55.81, SDAge = 7.72). Similarities between the UK Biobank and MindCrowd were assessed using a subset of MindCrowd (UKBb MindCrowd) selected to mirror the UK Biobank demographics (n total = 39,795, n women = 29,640, n men = 10,155; ages 40–70 years old, M Age = 56.59, SDAge = 8.16). An identical linear model (LM) was used to assess both cohorts. Analyses revealed similarities between MindCrowd and the UK Biobank across most results. Divergent findings from the UK Biobank included (1) a first-degree family history of Alzheimer’s disease (FHAD) was associated with longer cvrRT. (2) Men with the least education were associated with longer cvrRTs comparable to women across all educational attainment levels. Divergent findings from UKBb MindCrowd included more education being associated with shorter svRTs and a history of smoking with longer svRTs from younger to older ages.

Abstract Vascular contributions to cognitive impairment and dementia (VCID) include structural and functional blood vessel injuries linked to poor neurocognitive outcomes. Smoking might indirectly increase the likelihood of cognitive impairment by exacerbating vascular disease risks. Sex disparities in VCID have been reported, however, few studies have assessed the sex-specific relationships between smoking and memory performance and with contradictory results. We investigated the associations between sex, smoking, and cardiovascular disease with verbal learning and memory function. Using MindCrowd, an observational web-based cohort of ~ 70,000 people aged 18–85, we investigated whether sex modifies the relationship between smoking and cardiovascular disease with verbal memory performance. We found significant interactions in that smoking is associated with verbal learning performance more in women and cardiovascular disease more in men across a wide age range. These results suggest that smoking and cardiovascular disease may impact verbal learning and memory throughout adulthood differently for men and women.

To understand the genetic basis of complex traits, it is important to be able to efficiently phenotype many genetically distinct individuals. In the nematode Caenorhabditis elegans, individuals have been isolated from diverse populations around the globe and whole-genome sequenced. As a result, hundreds of wild strains with known genome sequences can be used for genome-wide association studies (GWAS). However, phenotypic analysis of these strains can be laborious, particularly for quantitative traits requiring multiple measurements per strain. Starvation resistance is likely a fitness-proximal trait for nematodes, and it is related to metabolic disease risk in humans. However, natural variation in C. elegans starvation resistance has not been systematically characterized, and precise measurement of the trait is time-intensive. Here, we developed a population-selection-and-sequencing-based approach to phenotype starvation resistance in a pool of 96 wild strains. We used restriction site-associated DNA sequencing (RAD-seq) to infer the frequency of each strain among survivors in a mixed culture over time during starvation. We used manual starvation survival assays to validate the trait data, confirming that strains that increased in frequency over time are starvation-resistant relative to strains that decreased in frequency. Further, we found that variation in starvation resistance is significantly associated with variation at a region on chromosome III. Using a near-isogenic line (NIL), we showed the importance of this genomic interval for starvation resistance. This study demonstrates the feasibility of using population selection and sequencing in an animal model for phenotypic analysis of quantitative traits, documents natural variation of starvation resistance in C. elegans, and identifies a genomic region that contributes to such variation.

Reduced insulin-like signaling is required for C. elegans response to many environmental stressors, but how distinct outcomes are achieved is unknown. The authors show that the cytosolic sulfotransferase SSU-1 controls neurohormonal signaling via NHR-1 to specify the animals’ osmotic stress response.

Summary: Standard laboratory culture of Caenorhabditis elegans utilizes solid growth media with a bacterial food source. However, this culture method limits control of food availability and worm population density, factors that impact many life-history traits. Here, we describe liquid-culture protocols for precisely modulating bacterial food availability and population density, facilitating reliable production of arrested L1 larvae, dauer larvae, dietarily restricted worms, or well-fed worms. Worms can be grown in small quantities for standard assays or in the millions for other applications.For complete details on the use and execution of these protocols, please refer to Hibshman et al. (2016), Webster et al. (2018), and Jordan et al. (2019).

Abstract Background Developmental physiology is very sensitive to nutrient availability. For instance, in the nematode Caenorhabditis elegans, newly hatched L1-stage larvae require food to initiate postembryonic development. In addition, larvae arrested in the dauer diapause, a non-feeding state of developmental arrest that occurs during the L3 stage, initiate recovery when exposed to food. Despite the essential role of food in C. elegans development, the contribution of food perception versus ingestion on physiology has not been delineated. Results We used a pharmacological approach to uncouple the effects of food (bacteria) perception and ingestion in C. elegans. Perception was not sufficient to promote postembryonic development in L1-stage larvae. However, L1 larvae exposed to food without ingestion failed to develop upon return to normal culture conditions, instead displaying an irreversible arrest phenotype. Inhibition of gene expression during perception rescued subsequent development, demonstrating that the response to perception without feeding is deleterious. Perception altered DAF-16/FOXO subcellular localization, reflecting activation of insulin/IGF signaling (IIS). The insulin-like peptide daf-28 was specifically required, suggesting perception in chemosensory neurons, where it is expressed, regulates peptide synthesis and possibly secretion. However, genetic manipulation of IIS did not modify the irreversible arrest phenotype caused by food perception, revealing that wild-type function of the IIS pathway is not required to produce this phenotype and that other pathways affected by perception of food in the absence of its ingestion are likely to be involved. Gene expression and Nile red staining showed that food perception could alter lipid metabolism and storage. We found that starved larvae sense environmental polypeptides, with similar molecular and developmental effects as perception of bacteria. Environmental polypeptides also promoted recovery from dauer diapause, suggesting that perception of polypeptides plays an important role in the life history of free-living nematodes. Conclusions We conclude that actual ingestion of food is required to initiate postembryonic development in C. elegans. We also conclude that polypeptides are perceived as a food-associated cue in this and likely other animals, initiating a signaling and gene regulatory cascade that alters metabolism in anticipation of feeding and development, but that this response is detrimental if feeding does not occur.

Fluctuations in nutrient availability profoundly impact gene expression. Previous work revealed postrecruitment regulation of RNA polymerase II (Pol II) during starvation and recovery in Caenorhabditis elegans, suggesting that promoter-proximal pausing promotes rapid response to feeding. To test this hypothesis, we measured Pol II elongation genome wide by two complementary approaches and analyzed elongation in conjunction with Pol II binding and expression. We confirmed bona fide pausing during starvation and also discovered Pol II docking. Pausing occurs at active stress-response genes that become downregulated in response to feeding. In contrast, “docked” Pol II accumulates without initiating upstream of inactive growth genes that become rapidly upregulated upon feeding. Beyond differences in function and expression, these two sets of genes have different core promoter motifs, suggesting alternative transcriptional machinery. Our work suggests that growth and stress genes are both regulated postrecruitment during starvation but at initiation and elongation, respectively, coordinating gene expression with nutrient availability.

Increasingly, evidence suggests a role for polyphenols in blood glucose control. The objective of this systematic review was to evaluate the effect of polyphenol-rich sources in combination with carbohydrate sources on resulting postprandial glycaemic and insulin responses. A literature search was conducted using Medline, CINHAL and Web of Science databases. Selected studies included randomised controlled trials in which the association of polyphenol-containing food or beverage consumption with a carbohydrate source and effect on acute postprandial glycaemia and/or insulin was reported. A total of thirteen full articles were included in the review. Polyphenol sources included coffee, black tea, fruit juice, plant extracts, berries and different rye breads, and carbohydrate sources included bread, pancakes and simple sugars such as sucrose, glucose and fructose. Although glycaemic and insulin responses differed depending on the polyphenol–carbohydrate combination, overall, polyphenol sources were shown to reduce the peak and early-phase glycaemic response and maintain the glycaemic response in the later stages of digestion. To a lesser extent, polyphenol sources were also shown to reduce peak insulin response and sustain the insulin response, especially when consumed with bread. This review supports epidemiological data suggesting that polyphenols in foods and beverages may have a beneficial effect on reducing the risk of type 2 diabetes. However, the extent of this effect is variable depending on the polyphenol and carbohydrate source.

The Deltatrac™ II Metabolic Monitor (Datex-Ohmeda Inc.) is considered the standard reference machine in indirect calorimetry; however, it is no longer commercially available thus there is a need for new machines. The gas exchange measurement (GEM; GEM Nutrition Ltd) and the ECAL (Health Professional Solutions) are alternative measuring systems. The aim of this study was to compare the ECAL and GEM with Deltatrac for measures of RMR and the GEM to the Deltatrac for measures of diet-induced thermogenesis (DIT). Twenty healthy participants were tested on test day 1 (T1) and test day 2 (T2). RMR was measured in a randomised order for 30 min on the Deltatrac, the GEM and the ECAL. Following this, a 1553 kJ meal was consumed and DIT was measured on the Deltatrac and the GEM in alternating 15 min intervals for 4 h. The GEM reported consistently higher values than the Deltatrac for VO2, VCO2, RMR and fat oxidation (P

Containment conditions after certain postulated severe accident scenarios in nuclear power plants might result in the accumulation of hydrogen in the vessel dome. Inspired by these accident scenarios an experiment for the OECD/NEA benchmark exercise (2014) was carried out in the large scale PANDA facility at the Paul Scherrer Institut in Switzerland. The benchmark experiment was conducted at room temperature and under conditions characterized by an initially positively buoyant jet which becomes negatively buoyant while interacting with a helium layer. The experiment addresses (i) the initial conditions especially at the tube exit and (ii) the details of the entrainment of the helium stratification into the jet and the transport of the mixture towards the lower parts of the vessel. For the tube exit velocity mean and fluctuating quantities we find a reasonable agreement with pipe flow data, but a lack of agreement between past tube exit measurements and our results. It is shown that the axial velocity of the jet experiences a strong deceleration in the vicinity of the helium-rich layer and is finally stopped. Fluid accumulates in this zone and part of this fluid is flowing back in a narrow annular region around the upward flowing jet. Consequently, part of the annular flow is reentrained into the rising jet. During the layer erosion, the flow structure changes from a more downwards oriented annular type to a more horizontally oriented mushroom type of flow. It is found that locations for which we record considerable turbulent kinetic energy k extends above the region where the velocity magnitude v has decayed to almost zero, indicating that the jet deceleration and redirection introduces considerable turbulence in the helium stratification.

A pictorial field guide to the 30 species of sandfly most commonly encountered in Pará State is presented, based on the easily recognised external characters of the length of the 5th palpal segment, thoracic infuscation, abdominal colour and head and body size. In most cases this allows identification to the species. In others, especially with females, it gives an indication of the species, which may then be confirmed with data from more detailed taxanomix studies. This type of field guide helps in teaching, rapid sorting of flies prior to dissection and in acquainting visitors with the variety of species present in a given area.A rapid technique for the taxonomic sorting of unmounted, freshly killed female sandflies is required, prior to the dissection of large numbers of a particular species. Such a method is useful in areas where numerous species occur in studies on natural flagellate infections, age determination and for ecological studies. With the above points in mind a pictorial field guide has been designed that enables the identification of unmounted, unmacerated specimens of the 30 more commonly encountered species of phleboto-mine sandflies (***) in Pará State, North Brazil. It is based on the easily recognised external characters of the length of the 5th palpal segment, thoracic infuscation, ad-dominal colour and proboscis and body size.Taxonomy of male phlebotomine sandflies is based on the structure of the genitalia and, as most of this is external, a wholly external character key is readily made. Female taxonomy, however, is based on the internal character of the cibarium, pharynx and sperma thecae. In order to produce an external character key we therefore return to an unso phisticated "phlebotometry" (see Martins et al., 1978 p. 3 for review), using relative lengths of the proboscis, palpal segments and body, along with the degree of infuscation. Ihis idea is not new; indeed many sandfly specialists presently use external characters to separate certain species (H. Fraiha, R. P. Lane, P. D. Ready, D. G. Young and R. D. Ward personal communications 1983 & 1984).A key used to separate five anthropophillic sandflies by Biagi (1966), in Mexico, was based mainly on palpal segment length and infuscation. Floch and Abonnenc (1952) stressed the use of relative lengths of palpal segments in their keys to the sandflies of French Guiana, and four members of the shannoni group have been similarly separated according to the degree of infuscation by Morales et al. (1982). The use of thoracic infuscation as a reliable character seems to be gaining favour, having been used by young & Fairchild (1974) and Ready & Fraiha (1981). Indeed Chariotis 1974) showed the usefulness of thoracic infuscation to sepenate 7 anthropophillic species, during studies onvesicular stomatitis in Panama. Identification using external characters is essential for work on viral isolations from sandflies, where bulk samples of whole sandflies are used.Perhaps the major advantage of a simple visual guide is for teaching purposes. Technical staff in this lnstitute are able to identify most of the species they encounter without having to use the standard, more unwieldly (and in many cases unavailable) internal character keys, and the guides presented below have allowed rapid species sorting prior to the dissection of sandflies in our leismaniasis study areas (Ryan et at. ,1985).

Lutzomyia furcata transmitted Leishmania chagasi to a hamster 10 days after being experimentally fed on an infected spleen. An individual female Psychodopygus carrerai carrerai that had fed on a hamster lesion caused by Leishmania mexicana amazonensis transmitted this parasite 6 days later to another hamster. Transmission electron microscopy of this fly's head revealed a small number of degenerate promastigotes in the foregut, but only a few were attached.O protozoário Leishmania (L.) chagasi foi transmitido experimentalmente a um hamster pela picada do flebotomíneo Lutzomyia furcata. Os insetos foram infectados através de uma membrana (pele de pinto), utilizando-se formas amastigotas provenientes do baço de um hamster infectado. O baço foi triturado em sangue de coelho. A L. (L.) amazonensis foi transmitida a um hamster pela picada do flebotomíneo Psychodopygus c. carrerai, previamente alimentado em lesão de pele de um outro hamster infectado com o parasita. O exame desse flebotomíneo, através de microscópio eletrônico, revelou um número pequeno de flagelados degenerados, livres no lumen do intestino anterior.

The males of the sandfly Lutzomyia longipalpis occur in two forms, one which bears a single pair of pale spots on tergite 4 and another in which an additional pair of spots characterizes tergite 3. Almost complete reproductive isolation between sumpatric populations of the two forms and between allopatric populations of the one-spot form has been reported (Ward et al., 1983). Micromorphological differences in cuticular structures on the spots have also been observed and may be sites of pheromone release (Lane & Ward, 1984). Detais of the known distribution of the two are based on the examination of new specimens captured in Brazil during 1982, as well as museum collections and specimens from other laboratories. Males with a single pair of pale spots have been found from Mexico to southern Brazil, whilst the two-spot form is found only from the state of Maranhão in North Brazil to Minas Gerais and the border with Paraguay. In the eastern area of Brazil the two forms occur sympatrically in some locations and separately in others.Os machos do flebótomo Lutzomyia longipalpis apresentam-se sob duas formas, uma que possui um par de manchas claras apenas no tergito 4, enquanto a outra distingue-se por possuir um par adicional de manchas claras no tergito 3. Isolamento reprodutivo foi observado entre populações simpátricas com as duas formas e também entre populações alopátricas da forma com um só par de manchas (Ward et al., 1983). Foram também constatadas diferenças micromorfológicas em estruturas vuticulares nas manchas, que talvez sejam locias de liberação de ferormônios (Lane & Ward, 1984). Machos com um único par de manchas claras são encontrados desde o México até o sul do Brasil, enquanto a forma com duas manchas é achada somente no Maranhão, no norte do Brasil, até Minas Gerais e a fronteira do Brasil com o Paraguai, ao sul. No leste do Brasil as duas formas são simpátricas em algumas localidades e alopátricas em outras. São apresentados detalhes da distribuição conhecida das duas formas baseados na observação de espécimens capturados no Brasil em 1982, ou vistos em coleções de museus ou recebidos de outros laboratórios.

L'auteur met en évidence des différences dans le taux de cicatrisation et le taux d'usure des ailes qui sont confirmées par la corrélation avec l'âge ovarien utilisé comme échelle de temps. Ces variations concernent Glossina morsitans submorsitans, G. medicorum, G. fusca fusca, G. palpalis gambiensis, G. longipalpis et G. tachinoides en Côte-d'Ivoire; G. morsitans morsitans et G. pallidipes au Zimbabwe; G. morsitans morsitans au Malawi; G. morsitans centralis en Zambie; G. longipennis et G. pallidipes en Somalie. Cette communication est la première concernant le taux de cicatrisation. Celui-ci indique, de même que l'usure des ailes, l'activité de la tsé-tsé mais peut aussi refléter la pression des prédateurs. Les lésions cuticulaires offrent une échelle grossière pour la diagnose de l'âge similaire à celle de l'usure des ailes. Les cicatrices dues à l'accouplement et celles dues à des blessures diffèrent en fonction des espèces et de leur habitat

Des captures continues de Glossina pallidipes ont été effectuées sur 1,2 ha le long de la rivière Shebeli, en Somalie, au moyen de pièges biconiques. La densité relative (D.R.), représentée par le nombre de mouches capturées par un piège en un jour, a diminué pendant 5 jours, puis s'est brusquement accrue en 24 h pour diminuer à nouveau pendant les 3 jours suivants. En appliquant à ces deux périodes les principes de la soustraction par piégeage, les densités de tsétsé sont respectivement estimées à 967 ± 251 et 953 ± 208 mâles, et à 1 865 ± 186 et 2 483 ± 128 femelles par hectare. Le principal facteur qui a probablement provoqué cette modification de la D.R. est l'apparition de fortes pluies entre les 2 périodes de capture. Ces pluies ont affecté directement la disponibilité des mouches pour les pièges, ou indirecte-ment en modifiant le comportement des phacochères qui, d'après les résultats de 123 analyses de repas de sang, constituent leur hôte préférentiel. On a également établi une relation avec les maximums journaliers de température, mais elle ne suffit pas à expliquer les variations de la D.R.

L'efficacité relative de différents pièges (pièges biconiques, pièges de Manitoba, pièges adhésifs diversement colorés, piège de Catts, piège à eau, pièges de Moloo et de Swynnerton) a été comparée par des méthodes faciles à mettre en ouvre et ayant déjà fait leurs preuves. Les pièges biconiques standards capturent au moins deux fois plus de Glossina palpalis s.l. et de G. morsitans centralis que tous les autres pièges, mais ils ne récoltent que peu de simulies ou de tabanides. Les pièges Manitoba capturent huit fois plus de Tabanus taeniola, T. gratus et T. par que les autres pièges. Les pièges adhésifs, à eau et Malaise récoltent diverses espèces, mais en très faibles quantités. La capture au filet à main sur un homme appât est comparée aux pièges biconiques et à des écrans adhésifs ou électriques portés à dos d'homme pour G. palpalis s.l., à la capture dans un véhicule en mouvement et aux pièges biconiques pour G. morsitans centralis. Des essaims suiveurs de cette dernière espèce ont été observés et capturés. Par contre, G. palpalis s.l. est peu attirée par l'homme. Le ton de la teinture bleue du matériel utilisé pour les pièges biconiques influe de façon décisive sur la capture de G. tachinoides, mais pas sur celle de G. palpalis s.l. La collecte de G. morsitans centralis à l'aide d'appareils mobiles fournit un grand nombre de mâles âgés et quelques jeunes femelles, alors qu'avec G. palpalis s.l. on n'obtient que de très faibles quantités de chacune de ces catégories. Par contre les pièges biconiques capturent, pour ces deux epèces, de grandes quantités de chaque sexe, avec une bonne représentation de tous les âges. L'inverse est vrai pour les femelles de Simulium damnosum s.l. qui approchent volontiers l'homme mais sont très peu attirées par les pièges biconiques. De petits nombres de conopides Stylogaster leonum, de G. pallicera et de G. fusca ont également été capturés par les pièges biconiques.

Fluctuations in nutrient availability profoundly impact gene expression. Previous work revealed postrecruitment regulation of RNA polymerase II (Pol II) during starvation and recovery in Caenorhabditis elegans, suggesting that promoter-proximal pausing promotes rapid response to feeding. To test this hypothesis, we measured Pol II elongation genome wide by two complementary approaches and analyzed elongation in conjunction with Pol II binding and expression. We confirmed bona fide pausing during starvation and also discovered Pol II docking. Pausing occurs at active stress-response genes that become downregulated in response to feeding. In contrast, "docked" Pol II accumulates without initiating upstream of inactive growth genes that become rapidly upregulated upon feeding. Beyond differences in function and expression, these two sets of genes have different core promoter motifs, suggesting alternative transcriptional machinery. Our work suggests that growth and stress genes are both regulated postrecruitment during starvation but at initiation and elongation, respectively, coordinating gene expression with nutrient availability.

A closed Lutzomyia longipalpis colony, from Ceará has been used to transmit Leishmania chagasi isolated from a fox in Pará state. The last time this colony was successfully used in similar transmission experiments was eight years (64 generations) ago indicating that this colony of Lu. longipalpis has fully maintained its vectorial capacity in spite of such a long period of maintainance in the laboratory.Lutzomyia longipalpis foi alimentado através de membrana com uma suspensão de macerado de fígado e baço em sangue desfibrinado de coelho. Este material foi originário de um hamster infectado com Leishmania chagasi, realimentado em hamsters limpos, transmitindo os parasitos em duas ocasiões. Esta mesma colônia de Lu. longipalpis, do Ceará, foi usada para a primeira transmissão há oito anos e 64 gerações atrás e não teve a capacidade vetorial diminuída.

Dissection of Lutzomyia longipalpis, captured in the São Luis focus of visceral Leishmaniasis revealed a 1.8% promastigote infection rate.Foram dissecados Lutzomyia longipalpis, capturados no foco de leishmaniose visceral na ilha de Sao Luis, Maranhao, sendo encontradas 1,8% com infeccao natural por promastigotas.