Beyond the pollination syndrome: nectar ecology and the role of diurnal and nocturnal pollinators in the reproductive success of Inga sessilis (Fabaceae)

Inga species present brush‐type flower morphology allowing them to be visited by distinct groups of pollinators. Nectar features in relation to the main pollinators have seldom been studied in this genus. To test the hypothesis of floral adaptation to both diurnal and nocturnal pollinators, we studied the pollination ecology of Inga sessilis, with emphasis on the nectar secretion patterns, effects of sequential removals on nectar production, sugar composition and the role of diurnal and nocturnal pollinators in its reproductive success. Inga sessilis is self‐incompatible and pollinated by hummingbirds, hawkmoths and bats. Fruit set under natural conditions is very low despite the fact that most stigmas receive polyads with sufficient pollen to fertilise all ovules in a flower. Nectar secretion starts in the bud stage and flowers continually secreting nectar for a period of 8 h. Flowers actively reabsorbed the nectar a few hours before senescence. Sugar production increased after nectar removal, especially when flowers were drained during the night. Nectar sugar composition changed over flower life span, from sucrose‐dominant (just after flower opening, when hummingbirds were the main visitors) to hexose‐rich (throughout the night, when bats and hawkmoths were the main visitors). Diurnal pollinators contributed less than nocturnal ones to fruit production, but the former were more constant and reliable visitors through time. Our results indicate I. sessilis has floral adaptations, beyond the morphology, that encompass both diurnal and nocturnal pollinator requirements, suggesting a complementary and mixed pollination system.     

Interaction of a Partially Disordered Antisigma Factor with Its Partner,the Signaling Domain of the TonB-Dependent Transporter HasR

Bacteria use diverse signaling pathways to control gene expression in response to external stimuli. In Gram-negative bacteria, the binding of a nutrient is sensed by an outer membrane transporter. This signal is then transmitted to an antisigma factor and subsequently to the cytoplasm where an ECF sigma factor induces expression of genes related to the acquisition of this nutrient. The molecular interactions involved in this transmembrane signaling are poorly understood and structural data on this family of antisigma factor are rare. Here, we present the first structural study of the periplasmic domain of an antisigma factor and its interaction with the transporter. The study concerns the signaling in the heme acquisition system (Has) of Serratia marcescens. Our data support unprecedented partially disordered periplasmic domain of an anti-sigma factor HasS in contact with a membrane-mimicking environment. We solved the 3D structure of the signaling domain of HasR transporter and identified the residues at the HasS−HasR interface. Their conservation in several bacteria suggests wider significance of the proposed model for the understanding of bacterial transmembrane signaling.     

From lignocellulosic residues to market: Production and commercial potential of xylooligosaccharides

The updated definition of prebiotic expands the range of potential applications in which emerging xylooligosaccharides (XOS) can be used. It has been demonstrated that XOS exhibit prebiotic effects at lower amounts compared to others, making them competitively priced prebiotics. As a result, the industry is focused on developing alternative approaches to improve processes efficiency that can meet the increasing demand while reducing costs. Recent advances have been made towards greener and more efficient processes, by applying process integration strategies to produce XOS from costless lignocellulosic residues and using genetic engineering to create microorganisms that convert these residues to XOS. In addition, collecting more in vivo data on their performance will be key to achieve regulatory claims, greatly increasing XOS commercial value.     

Identification of Bacillus thuringiensis subsp. kurstaki strain HD1-Like bacteria from environmental and human samples after aerial spraying of Victoria, British Columbia, Canada, with Foray 48B

Aerial applications of Foray 48B, which contains Bacillus thuringiensis strain HD1, were carried out on 9 to 10 May, 19 to 21 May, and 8 to 9 June 1999 to control European gypsy moth (Lymantria dispar) populations in Victoria, British Columbia, Canada. A major assessment of the health impact of B. thuringiensis subsp. kurstaki was conducted by the Office of the Medical Health Officer of the Capital Health Region during this period. Environmental (air and water) and human (nasal swab) samples, collected before and after aerial applications of Foray 48B, both in the spray zone and outside of the spray zone, were analyzed for the presence of strain HD1-like bacteria. Random amplified polymorphic DNA analysis, cry gene-specific PCR, and dot blot DNA hybridization techniques were used to screen over 11,000 isolates of bacteria. We identified bacteria with genetic patterns consistent with those of B. thuringiensis subsp. kurstaki HD1 in 9,102 of 10,659 (85.4%) isolates obtained from the air samples, 13 of 440 (2.9%) isolates obtained from the water samples, and 131 of 171 (76.6%) isolates from the nasal swab samples. These analyses suggest that B. thuringiensis subsp. kurstaki HD1-like bacteria were present both in the environment and in the human population of Victoria prior to aerial applications of Foray 48B. The presence of B. thuringiensis subsp. kurstaki HD1-like bacteria in human nasal passages increased significantly after the application of Foray 48B, both inside and outside the spray zone.     

The matrilineal ancestry of Ashkenazi Jewry: portrait of a recent founder event

Both the extent and location of the maternal ancestral deme from which the Ashkenazi Jewry arose remain obscure. Here, using complete sequences of the maternally inherited mitochondrial DNA (mtDNA), we show that close to one-half of Ashkenazi Jews, estimated at 8,000,000 people, can be traced back to only 4 women carrying distinct mtDNAs that are virtually absent in other populations, with the important exception of low frequencies among non-Ashkenazi Jews. We conclude that four founding mtDNAs, likely of Near Eastern ancestry, underwent major expansion(s) in Europe within the past millennium.     

Evolutionary history of the European free-tailed bat,a tropical affinity species spanning across the Mediterranean Basin

The Mediterranean Basin is a global biodiversity hotspot, hosting a number of native species belonging to families that are found almost exclusively in tropical climates. Yet, whether or not these taxa were able to survive in the Mediterranean region during the Quaternary climatic oscillations remains unknown. Focusing on the European free-tailed bat (Tadarida teniotis), we aimed to (a) identify potential ancient populations and glacial refugia; (b) determine the post-glacial colonization routes across the Mediterranean; and (c) evaluate current population structure and demography. Mitochondrial and nuclear markers were used to understand T. teniotis evolutionary and demographic history. We show that T. teniotis is likely restricted to the Western Palearctic, with mitochondrial phylogeny suggesting a split between an Anatolian/Middle East clade and a European clade. Nuclear data pointed to three genetic populations, one of which is an isolated and highly differentiated group in the Canary Islands, another distributed across Iberia, Morocco, and France, and a third stretching from Italy to the east, with admixture following a pattern of isolation by distance. Evolutionary and demographic reconstruction supports a pre-Last Glacial Maximum (LGM) colonization of Italy and the Anatolian/Middle East, while the remaining populations were colonized from Italy after the Younger Dryas. We also found support for demographic expansion following the Iberian colonization. The results show that during the LGM T. teniotis persisted in Mediterranean refugia and has subsequently expanded to its current circum-Mediterranean range. Our findings raise questions regarding the physiological and ecological traits that enabled species with tropical affinities to survive in colder climates.     

Effects of general,specific and combined warm-up on explosive muscular performance

The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU.     

Hydration, thermoregulation, and performance effects of two sport drinks during soccer training sessions

In the present study, we aimed to compare the thermoregulatory response and soccer-specific training performance aspects of two commercially available sport drinks, both of similar carbohydrate concentration, but one containing 5.2% glycerol. Ten players participated in two similar outdoor training sessions and were randomly assigned to each of two drinks: a carbohydrate (C) beverage or a carbohydrate-glycerol (CG) beverage. Players consumed 500 mL of C or CG 30 minutes pre-exercise and at half-time. Pre- and postexercise body mass, core temperature (CT), and heart rate (HR) were recorded, and urine and blood samples were taken. No difference was observed between days for wet bulb globe temperature (session 1: 17.0 +/- 1.1 degrees C, session 2: 16.9 +/- 1.1 degrees C; P = 0.944). The degree of dehydration (% Delta BM) was greater after the C trial (P = 0.041). Similarly, percent change in plasma volume was greater in the C trial (P = 0.049). No overall main affect was observed between CT and mean exercise HRs during either training session (CT: P = 0.350; mean HR: P = 0.256), and there was no difference observed between groups in time to failure during the session-ending fatigue test (P = 0.547). Ingestion of a CG beverage provided players with better hydration than C alone. However, if training sessions are short (<75 minute), with adequate time for recovery, both drinks are sufficient for maintaining performance intensities during soccer-specific training.     

Manihot alterniflora and M. elongata spp. nov. (Euphorbiaceae) and the rediscovery of M. quinquefolia in Caatinga (semiarid) vegetation in Brazil

We describe and illustrate two species of Manihot that occur in Caatinga (semiarid) vegetation in Brazil and redescribe and lectotypify M. quinquefolia Pohl, which was only known from a single collection made by J. E. B. Pohl in 1827. Manihot elongata P.Carvalho & M.Martins is widely distributed and Manihot alterniflora P.Carvalho & M.Martins is endangered because of its small populations and restricted area of occurrence. We establish M. quinquefolia as the only species of Manihot in the Caatinga with compound leaves. An identification key is provided for the 13 species of Manihot present in the Caatinga.