Effects of marigold on the behavior,survival and nutrient reserves of <Emphasis Type="Italic">Aphidius Platensis</Emphasis>

Marigolds (Tagetes erecta L.) suppress nematodes and are attractive companion plants, but their role in biological control is unknown. We evaluated how exposure to marigold blooms impacts the aphid parasitoid, Aphidius platensis Brethes. Female wasps previously exposed to marigold spent more time walking and parasitizing Myzus percisae Sulzer or Schizaphis graminum Rodani aphids, and subsequently had higher parasitism rates. Meanwhile, completely starved wasps spent more time stationary and marginally more time grooming. Time spent probing, emergence rate, and sex ratio were not affected. Wasp survival was best on honey, followed by marigold, and lowest on non-blooming marigolds. Nutrient reserves of wasps given honey, aphid-infested marigold, or marigold alone were compared to newly-emerged unfed wasps. Their resulting lipid, glycogen and sugar levels were similar, suggesting that these foods helped wasps maintain reserves similar to emergence levels. These results suggest that marigold may improve biological control of aphids by A. platensis.     

A special issue of Biophysical Reviews dedicated to the 20th IUPAB (virtual) Congress “in” Foz do Iguaçu

The 20th IUPAB Congress took place online, together with the annual meetings of the Brazilian Biophysical Society and the Brazilian Society for Biochemistry and Molecular Biology, from the 4th to the 8th of October, 2021. The ten keynote lectures, 24 symposia, two poster sessions, and a series of technical seminars covered the full diversity of current biophysical research and its interfaces with other fields. The event had over 1000 attendees, with an excellent gender balance. Although the Americas dominated, there were also significant numbers of participants from Europe, Asia, and Africa.

The International Union of Pure and Applied Biophysics (IUPAB) came into existence in Stockholm in 1961 and has been a member of the International Science Council since 1966 (Solomon 1968). Its overall objectives aim to foster international collaboration in all aspects of biophysics and related areas and to catalyze the advancement of basic biophysical research as well as its many applications. Although IUPAB is active on many fronts, undeniably one of its showcase events is the IUPAB Congress, traditionally organized every three years in different locations worldwide. In 2021, the event was organized and run from Brazil, albeit for the very first time in a virtual format due to travel restrictions imposed by the COVID-19 pandemic. On this occasion, the Congress was organized in conjunction with the annual meetings of both the Brazilian Biophysical Society (SBBf, in its 45th edition) and the Brazilian Society for Biochemistry and Molecular Biology (SBBq, in its 50th edition). Even with the united forces of these well-established local societies, it turned out to be a bumpy ride to bring the event to fruition.Plans for the 20th Congress began in 2016, almost immediately after the decision to hold the event in Brazil, a cause championed by the then-president of the Brazilian Biophysical Society, Marcelo Morales. The original plans had the meeting to be held in the Cidade Maravilhosa (The Wonderful City) of Rio de Janeiro in October 2020. However, it soon became apparent that the political and economic difficulties that the State of Rio was facing at the time meant that it would be wise to search for an alternative venue. The previous experience of SBBq in organizing similar events in the city of Foz do Iguaçu, on the borders with Argentina and Paraguay, made this an obvious choice. Furthermore, the natural attraction of the spectacular Iguaçu waterfalls seemed to be an ideal compensation for Sugar Loaf Mountain, Copacabana beach, and the statue of Christ the Redeemer on Corcovado Mountain.Then came the pandemic. By mid-2020, it had become apparent that there were too many unknowns to make it possible to proceed with an in-person event in October of that year. It was decided to postpone the congress to 2021 but with a firm belief that things would be “back to normal.” Sweet delusion! As 2020 turned into 2021 and the severity and longevity of the pandemic became clearer and clearer (not to mention the abysmal performance of the Brazilian government in failing to rise to the challenge), the inevitable decision was taken to transform the event into an “on-line” congress. This was a first for both the local organizers and the IUPAB.The move to an online format immediately had an impact on the organization of the Young Scientist Program. This was initially envisaged to be a combination of formal and informal activities aimed at uniting about 40 early carrier scientists and post-docs for a couple of days prior to the main event in a stimulating atmosphere conducive to networking. Skillfully conceived, organized, and executed by Eneida de Paula (Campinas) and Eduardo Reis (São Paulo), this too had to be adapted to a “virtual reality.” The successful solution turned out to be a series of fortnightly thematic webinars, including a talk from a recognized authority in the field followed by three or four short presentations from the participants themselves (Table ​(Table1).1). The standard was extremely high and the YSP ended up being a highly effective warm-up to the congress itself. Furthermore, there was excellent geographical diversity among the participants with Europe, Africa, Asia, the Middle East, and both North and South America represented.Table 1Young Scientist Webinar Program

Chiral recognition by the copper(II) complex of 6-deoxy-6-N-(2-methylaminopyridine)-β-cyclodextrin

A modified β-cyclodextrin bearing a 2-aminomethylpyridine binding site for copper(II) (6-deoxy-6-[N-(2-methylamino)pyridine)]-β-cyclodextrin, CDampy was synthesized by C₆-monofunctionalization. The acid-base properties of the new ligand in aqueous solution were investigated by potentiometry and calorimetry, and its conformations as a function of pH were studied by NMR and circular dichroism (c.d.). The formation of binary copper(II) complexes was studied by potentiometry, EPR, and c.d. The copper(II) complex was used as chiral selector for the HPLC enantiomeric separation of underivatized aromatic amino acids. Enantioselectivity in the overall stability constants of the ternary complexes with D- or L-Trp was detected by potentiometry, whereas the complexes of the Ala enantiomers did not show any difference in stability. These results were consistent with a preferred cis coordination of the amino group of the ligand and of the amino acid in the ternary complexes (“cis effect”), which leads to the inclusion of the aromatic side chain of D-Trp, but not of that of L-Trp. In Trp-containing ternary complexes, the two enantiomers showed differences in the fluorescence lifetime distribution, consistent with only one conformer of D-Trp and two conformers of L-Trp, and the latter were found to be more accessible to fluorescence quenching by acrylamide and KI. Chirality 9:341–349, 1997. © 1997 Wiley-Liss, Inc.     

In vivo and in silico anti-inflammatory mechanism of action of the semisynthetic (−)-cubebin derivatives (−)-hinokinin and (−)-O-benzylcubebin

(?)-Cubebin (CUB), isolated from seeds of Piper cubeba, was used as starting material to obtain the derivatives (?)-hinokinin (HK) and (?)-O-benzyl cubebin (OBZ). Using paw edema as the experimental model and different chemical mediators (prostaglandin and dextran), it was observed that both derivatives were active in comparison with both negative (5% Tween® 80 in saline) and positive (indomethacin) controls. The highest reduction in the prostaglandin-induced edema was achieved by OBZ (66.0%), while HK caused a 59.2% reduction. Nonetheless, the dextran-induced paw edema was not significantly reduced by either of the derivatives (HK or OBZ), which inhibited edema formation by 18.3% and 3.5%, respectively, in contrast with the positive control, cyproheptadine, which reduced the edema by 56.0%. The docking analysis showed that OBZ presented the most stable ligand-receptor (COX-2 – cyclooxygenase-2) interaction in comparison with CUB and HK.     

Biophysical aspects of biomineralization

During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix (ECM) by promoting the synthesis of hydroxyapatite (HA) seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Several lipid and proteins present in the membrane of the MVs mediate the interactions of MVs with the ECM and regulate the initial mineral deposition and posterior propagation. Among the proteins of MV membranes, ion transporters control the availability of phosphate and calcium needed for initial HA deposition. Phosphatases (orphan phosphatase 1, ectonucleotide pyrophosphatase/phosphodiesterase 1 and tissue-nonspecific alkaline phosphatase) play a crucial role in controlling the inorganic pyrophosphate/inorganic phosphate ratio that allows MV-mediated initiation of mineralization. The lipidic microenvironment can help in the nucleation process of first crystals and also plays a crucial physiological role in the function of MV-associated enzymes and transporters (type III sodium-dependent phosphate transporters, annexins and Na⁺/K⁺ ATPase). The whole process is mediated and regulated by the action of several molecules and steps, which make the process complex and highly regulated. Liposomes and proteoliposomes, as models of biological membranes, facilitate the understanding of lipid–protein interactions with emphasis on the properties of physicochemical and biochemical processes. In this review, we discuss the use of proteoliposomes as multiple protein carrier systems intended to mimic the various functions of MVs during the initiation and propagation of mineral growth in the course of biomineralization. We focus on studies applying biophysical tools to characterize the biomimetic models in order to gain an understanding of the importance of lipid–protein and lipid–lipid interfaces throughout the process.     

Short‐term physiological plasticity: Trade‐off between drought and recovery responses in three Mediterranean Cistus species

Short‐term physiological plasticity allows plants to thrive in highly variable environments such as the Mediterranean ecosystems. In such context, plants that maximize physiological performance under favorable conditions, such as Cistus spp., are generally reported to have a great cost in terms of plasticity (i.e., a high short‐term physiological plasticity) due to the severe reduction of physiological performance when stress factors occur. However, Cistus spp. also show a noticeable resilience ability in response to stress factors. We hypothesized that in Cistus species the short‐term physiological response to stress and that to subsequent recovery can show a positive trade‐off to offset the costs of the photosynthetic decline under drought. Gas exchange, chlorophyll fluorescence, and water relations were measured in C. salvifolius, C. monspeliensis, and C. creticus subsp. eriocephalus during an imposed experimental drought and subsequent recovery. Plants were grown outdoor in common garden conditions from seeds of different provenances. The short‐term physiological response to stress and that to recovery were quantified via phenotypic plasticity index (PI_stress and PI_recovery, respectively). A linear regression analysis was used to identify the hypothesized trade‐off PI_stress–PI_recovery. Accordingly, we found a positive trade‐off between PI_stress and PI_recovery, which was consistent across species and provenances. This result contributes in explaining the profit, more than the cost, of a higher physiological plasticity in response to short‐term stress imposition for Cistus spp because the costs of a higher PI_stress are payed back by an as much higher PI_recovery. The absence of leaf shedding during short‐term drought supports this view. The trade‐off well described the relative variations of gas exchange and water relation parameters. Moreover, the results were in accordance with the ecology of this species and provide the first evidence of a consistent trade‐off between the short‐term physiological responses to drought and recovery phases in Mediterranean species.     

Anthropometry and body composition of 18 year old men according to duration of breast feeding: birth cohort study from Brazil

Objective To assess the association between duration of breast feeding and measures of adiposity in adolescence.Design Population based birth cohort study.Setting Pelotas, a city of 320 000 inhabitants in a relatively developed area in southern Brazil.Participants All newborn infants in the city''s hospitals were enrolled in 1982; 78.8% (2250) of all male participants were located at age 18 years when enrolling in the national army.Main outcome measures Weight, height, sitting height, subscapular and triceps skinfolds, and body composition (body fat, lean mass).Results Neither the duration of total breast feeding nor that of predominant breast feeding (breast milk plus non-nutritive fluids) showed consistent associations with anthropometric or body composition indices. After adjustment for confounding factors, the only significant associations were a greater than 50% reduction in obesity among participants breast fed for three to five months compared with all other breastfeeding categories (P = 0.007) and a linear decreasing trend in obesity with increasing duration of predominant breast feeding (P = 0.03). Similar significant effects were not observed for other measures of adiposity. Borderline direct associations also occurred between total duration of breast feeding and adult height (P = 0.06).Conclusions The significant reduction in obesity among children breast fed for three to five months is difficult to interpret, as no a priori hypothesis existed regarding a protective effect of intermediate duration of breast feeding. The findings indicate that, in this population, breast feeding has no marked protective effect against adolescent adiposity.     

Giant Vesicles under Oxidative Stress Induced by a Membrane-Anchored Photosensitizer

We have synthesized the amphiphile photosensitizer PE-porph consisting of a porphyrin bound to a lipid headgroup. We studied by optical microscopy the response to light irradiation of giant unilamellar vesicles of mixtures of unsaturated phosphatidylcholine lipids and PE-porph. In this configuration, singlet oxygen is produced at the bilayer surface by the anchored porphyrin. Under irradiation, the PE-porph decorated giant unilamellar vesicles exhibit a rapid increase in surface area with concomitant morphological changes. We quantify the surface area increase of the bilayers as a function of time and photosensitizer molar fraction. We attribute this expansion to hydroperoxide formation by the reaction of the singlet oxygen with the unsaturated bonds. Considering data from numeric simulations of relative area increase per phospholipid oxidized (15%), we measure the efficiency of the oxidative reactions. We conclude that for every 270 singlet oxygen molecules produced by the layer of anchored porphyrins, one eventually reacts to generate a hydroperoxide species. Remarkably, the integrity of the membrane is preserved in the full experimental range explored here, up to a hydroperoxide content of 60%, inducing an 8% relative area expansion.