Read by QxMD icon Read


Jiamin Sun, Libin Zhang, Yang Pan, Chenggang Lin, Fang Wang, Hongsheng Yang
This study used controlled laboratory conditions to directly assess the role of water temperature in controlling diel feeding and locomotion behaviours, and digestive physiology in the sea cucumber Apostichopus japonicus The results revealed that both the proportion of feeding individuals and ingestion rate were highest at 16 °C. Regardless of water temperatures, sea cucumbers appeared to be nocturnal and their peak feeding activity occurred at 00:00-04:00. Tentacle insertion rate was not significantly correlated with water temperature (< 24 °C)...
April 3, 2018: Journal of Experimental Biology
Ace R North, H Charles J Godfray
BACKGROUND: Populations of the Anopheles gambiae complex are found during the rainy season throughout West Africa, even in arid areas with long dry seasons during which mosquitoes appear to be absent. Several hypotheses have been proposed to explain this apparent paradox, including aestivation, dispersal between neighbouring settlements, and long distance migration using high-altitude wind currents. METHODS: An individual-based, spatially explicit model of mosquito populations was developed for a region of West Africa centred on, and including all of, Burkina Faso...
April 2, 2018: Malaria Journal
Miho S Kitazawa, Koichi Fujimoto
Stabilization and variation of floral structures are indispensable for plant reproduction and evolution; however, the developmental mechanism regulating their structural robustness is largely unknown. To investigate this mechanism, we examined positional arrangement (aestivation) of excessively produced perianth organs (tepals) of six- and seven-tepaled (lobed) flowers in six Anemone species (Ranunculaceae). We found that the tepal arrangement that occurred in nature varied intraspecifically between spiral and whorled arrangements...
March 27, 2018: Journal of Plant Research
Salvatore Arpaia, Ferdinando Baldacchino, Sara Bosi, Giovanni Burgio, Simona Errico, Rosaria Alessandra Magarelli, Antonio Masetti, Salvatore Santorsola
Environmental impacts of genetically modified crops are mandatorily assessed during their pre-market phase. One of the areas of concern is the possible impact on non-target organisms. Crops expressing Cry toxins might affect Lepidoptera larvae living outside cultivated fields, through pollen deposition on wild plants which constitute their food source. While pollen toxicity varies among different events, possible exposure of non-target species depends on the agro-environmental conditions. This study was conducted in two protected areas in Italy, characterized by different climatic conditions, where many Lepidoptera species thrive in proximity to maize cultivations...
March 23, 2018: Insect Science
Rodrigo S B Gavira, Marina R Sartori, Manuel N Gontero-Fourcade, Bruna F Gomes, Augusto S Abe, Denis V Andrade
Tegu lizards ( Salvator merianae ) aestivate for up to 5 months during Brazil's winter, when they retreat to burrows and halt most activities. Dormant tegus reduce their gastrointestinal (GI) mass, which allows a substantial energy economy. This strategy, however, implies that the first post-dormancy digestion would be more costly than subsequent feeding episodes as a result of GI atrophy. To address this, we determined the postprandial metabolic response (SDA) of the first (M1), second (M2) and several (RM) feeding episodes after tegus' dormancy...
April 19, 2018: Journal of Experimental Biology
K Hidalgo, C Montazeau, D Siaussat, V Braman, M Trabalon, F Simard, D Renault, R K Dabiré, K Mouline
Aestivation and dispersive migration are the two strategies evoked in the literature to explain the way in which malaria vectors Anopheles coluzzii and A. gambiae survive the harsh climatic conditions of the dry season in sub-Saharan Africa. However, the physiological mechanisms regulating these two strategies are unknown. In the present study, mosquito species were exposed to controlled environmental conditions mimicking the rainy and dry seasons of south western Burkina Faso. Survival strategies were studied through morphometric (wing length), ecophysiological (respiratory gas exchanges), biochemical (cuticular hydrocarbons composition) and molecular (AKH mRNA expression levels) parameters, variations of which are usually considered to be hallmarks of aestivation and dispersion mechanisms in various insects...
March 21, 2018: Journal of Experimental Biology
Neal J Dawson, Yulia Biggar, Amal I Malik, Kenneth B Storey
The African clawed frog, Xenopus laevis, can withstand extremely arid conditions through aestivation, resulting in dehydration and urea accumulation. Aestivating X. laevis reduce their metabolic rate, and rely on anaerobic glycolysis to meet reduced ATP demands. The present study investigated how severe dehydration affected the transcript levels, kinetic profile, and phosphorylation state of the key glycolytic enzyme pyruvate kinase (PK) in the liver and skeletal muscle of X. laevis. Compared to control frogs, severely dehydrated frogs showed an increase in the transcript abundance of both liver and muscle isoforms of PK...
January 10, 2018: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
Mervyn Singer
An exaggerated, dysregulated host response to insults such as infection (i.e. sepsis), trauma and ischaemia-reperfusion injury can result in multiple organ dysfunction and death. While the focus of research in this area has largely centred on inflammation and immunity, a crucial missing link is the precise identification of mechanisms at the organ level that cause this physiological-biochemical failure. Any hypothesis must reconcile this functional organ failure with minimal signs of cell death, availability of oxygen, and (often) minimal early local inflammatory cell infiltrate...
December 28, 2017: Critical Care: the Official Journal of the Critical Care Forum
Diana L Huestis, Monica L Artis, Peter A Armbruster, Tovi Lehmann
BACKGROUND: Throughout large parts of sub-Saharan Africa, seasonal malaria transmission follows mosquito density, approaching zero during the dry season and peaking during the wet season. The mechanisms by which malaria mosquitoes survive the long dry season, when no larval sites are available remain largely unknown, despite being long recognized as a critical target for vector control. Previous work in the West African Sahel has led to the hypothesis that Anopheles coluzzii (formerly M-form Anopheles gambiae) undergoes aestivation (dry-season diapause), while Anopheles gambiae (s...
December 27, 2017: Parasites & Vectors
Ke Xu, Qiuhan Yu, Jianshe Zhang, Zhenming Lv, Wandong Fu, Tianming Wang
The sea cucumber Apostichopus japonicus (Selenka) commonly undergoes aestivation in response to high water temperatures. This process is accompanied by tissue regression and body mass reduction. Previous studies have suggested that apoptosis may play a role in the tissue remodeling that occurs during aestivation, although this has not definitively been shown. To investigate this hypothesis, the present study used A. japonicus as a model organism to examine cell loss through apoptosis in intestinal degeneration during aestivation...
February 2018: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
You R Chng, Jasmine L Y Ong, Biyun Ching, Xiu L Chen, Kum C Hiong, Wai P Wong, Shit F Chew, Siew H Lam, Yuen K Ip
African lungfishes are ammonotelic in water. They can aestivate for long periods on land during drought. During aestivation, the gills are covered with dried mucus and ammonia excretion ceases. In fishes, ammonia excretion through the gills involves Rhesus glycoproteins (RhGP/Rhgp). This study aimed to obtain the complete cDNA coding sequences of rhgp from the gills of Protopterus annectens, and to determine their branchial mRNA and protein expression levels during the induction, maintenance and arousal phases of aestivation...
2017: PloS One
Mukesh K Dhillon, Fazil Hasan
Temperature-dependent development rate, percent diapause induction (hibernation at low temperature and aestivation at high temperature), and survival of diapausing larvae of Chilo partellus (Swinhoe, 1885) were examined on 13 constant temperatures ranging from 8 to 40°C. Development of hibernating and aestivating larvae occurred from 10 to 25°C and 27-38°C, respectively. However, no development occurred at 8°C and 40°C. To determine actual thermal conditions that affect development and trigger both kind of diapause (hibernation and aestivation), various thermal parameters were estimated by fitting the development rate data to two linear (Ordinary equation and Ikemoto & Takai) models and thirteen non-linear models...
October 2017: Journal of Thermal Biology
Francisco Javier Zamora-Camacho, Mar Comas
Global amphibian decline is due to several factors: habitat loss, anthropization, pollution, emerging diseases, and global warming. Amphibians, with complex life cycles, are particularly susceptible to habitat alterations, and their survival may be impaired in anthropized habitats. Increased mortality is a well-known consequence of anthropization. Life-history theory predicts higher reproductive investment when mortality is increased. In this work, we compared age, body size, and different indicators of reproductive investment, as well as prey availability, in natterjack toads (Epidalea calamita) from agrosystems and adjacent natural pine groves in Southwestern Spain...
2017: PeerJ
Angela M Mech, Sherilyn J Harper, Nathan P Havill, Carol D von Dohlen, Gaelen R Burke
Bacterial endosymbionts of sap-sucking insects provide their host with a number of beneficial qualities, including the supply of nutrition, defense against parasitoids, and protection from heat stress. Damage to these bacterial associates can therefore have a negative impact on the fitness of their insect host. We evaluated observational and experimental factors regarding the non-native hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae) to help understand the roles of its three recently identified symbionts, including under heat stress conditions...
August 9, 2017: Insect Science
Tovi Lehmann, David Weetman, Diana L Huestis, Alpha S Yaro, Yaya Kassogue, Moussa Diallo, Martin J Donnelly, Adama Dao
In arid environments, the source of the malaria mosquito populations that re-establish soon after first rains remains a puzzle and alternative explanations have been proposed. Using genetic data, we evaluated whether the early rainy season (RS) population of Anopheles coluzzii is descended from the preceding late RS generation at the same locality, consistent with dry season (DS) dormancy (aestivation), or from migrants from distant locations. Distinct predictions derived from these two hypotheses were assessed, based on variation in 738 SNPs in eleven A...
August 2017: Evolutionary Applications
Aristeidis Parmakelis, Panayiota Kotsakiozi, Christos K Kontos, Panagiotis G Adamopoulos, Andreas Scorilas
BACKGROUND: Cornu aspersum is a quite intriguing species from the point of view of ecology and evolution and its potential use in medical and environmental applications. It is a species of economic importance since it is farmed and used for culinary purposes. However, the genomic tools that would allow a thorough insight into the ecology, evolution, nutritional and medical properties of this highly adaptable organism, are missing. In this work, using next-generation sequencing (NGS) techniques we assessed a significant portion of the transcriptome of this non-model organism...
June 28, 2017: BMC Genomics
Yosef Hyams, Guy Paz, Claudette Rabinowitz, Baruch Rinkevich
Rough environmental conditions make the survival of many multi-cellular organisms almost impossible, enforcing behavioral, morphological, physiological and reproductive rejoinders that can cope with harsh times and hostile environments, frequently through down-regulation of metabolism into basal states of dormancy, or torpor. This study examines one of the most unique torpor strategies seen within the phylum Chordata, exhibited by the colonial urochordate Botrylloides leachi, which enters a state of hibernation or aestivation in response to thermal stress, during which all of its functional colonial units (zooids) are entirely absorbed and the colony survives as small remnants of the vasculature, lacking both feeding and reproduction organs...
August 1, 2017: Developmental Biology
D L Mausel, L T Kok, S M Salom
To determine if key attributes for a successful biological control agent are possessed by the predator, Laricobius nigrinus Fender, field studies were conducted in its native range of Seattle, WA. The relationship between adult and immature L. nigrinus abundance to different densities of its prey, Adelges tsugae Annand, were determined. In a second study, predator and prey densities, and survivorship of each sistens A. tsugae stage were determined to gauge the impact of predation. The predator strongly aggregated and increased its reproduction when prey density increased, the two mechanisms of a numerical response...
June 1, 2017: Environmental Entomology
Carla Bonetti Madelaire, Inna Sokolova, Fernando Ribeiro Gomes
Elevated androgens and glucocorticoids displayed by males during the reproductive season have been proposed to mediate a possible trade-off between reproduction and immunocompetence. Anurans living in arid and semiarid environments display a strong seasonal reproduction, which could accentuate the variation in physiological, immunological, and behavioral parameters. We studied covariation between steroid plasma levels, morphometric variables associated with body condition and immunity, leukocyte profile, parasite load, and response to an immunological challenge across different phases of the annual life-history cycle of three anuran species from a Brazilian semiarid area...
July 2017: Physiological and Biochemical Zoology: PBZ
Roy Faiman, Samantha Solon-Biet, Margery Sullivan, Diana L Huestis, Tovi Lehmann
BACKGROUND: Variation in longevity has long been of interest in vector biology because of its implication in disease transmission through vectorial capacity. Recent studies suggest that Anopheles coluzzii adults persist during the ~7 month dry season via aestivation. Recently there has been a growing body of evidence linking dietary restriction and low ratio of dietary protein to carbohydrate with extended longevity of animals. Here, we evaluated the effects of dietary restriction and the protein : carbohydrate ratio on longevity of An...
March 24, 2017: Parasites & Vectors
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"