Cuticle expansion during feeding in the tick Amblyomma hebraeum (Acari: Ixodidae): The role of hydrostatic pressure

Female Amblyomma hebraeum ticks (Acari: Ixodidae) increase their weight ∼10-fold during a ‘slow phase of engorgement’ (7–9 days), and a further 10-fold during the ‘rapid phase’ (12–24 h). During the rapid phase, the cuticle thins by half, with a plastic (permanent) deformation of greater than 40% in two orthogonal directions. A stress of 2.5 MPa or higher is required to achieve this degree of deformation (Flynn and Kaufman, 2015). Using a dimensional analysis of the tick body and applying the Laplace equation, we calculated that the tick must achieve high internal hydrostatic pressures in order to engorge fully: greater than 55 kPa at a fed:unfed mass ratio of ∼20:1, when cuticle thinning commences (Flynn and Kaufman, 2011). In this study we used a telemetric pressure transducer system to measure the internal hydrostatic pressure of ticks during feeding. Sustained periods of irregular high frequency (>20 Hz) pulsatile bursts of high pressure (>55 kPa) were observed in two ticks: they had been cannulated just prior to the rapid phase of engorgement, and given access to a host rabbit for completion of the feeding cycle. The pattern of periods of high pressure generation varied over the feeding cycle and between the two specimens. We believe that these pressures exceed those reported so far for any other animal.     

The correlation between tick (Ixodes persulcatus Sch.) questing behaviour and synganglion neuronal responses to odours

We examined the behavioural and electrophysiological responses of taiga ticks (Ixodes persulcatus) to several olfactory stimuli: Osmopherone® (5-a-androst-16-en-3-ol), Osmopherine® (butanoic and 3-methylbutanoic acids), DEET® (N,N-diethyl-meta-toluamide), ethanol (96%), and water (control stimulus). To study individual tick behavioural reactions to these stimuli, we used a Y-shaped glass maze (n = 50). To study the electrophysiological reactions of the ticks’ synganglia to these olfactory stimuli, we recorded the shifts of total potential (TP) of pre-oesophageal neurons in response to odour stimulation of Haller’s organ (n = 25). We found that Osmopherine® attracted ticks and frequently evoked negative shifts of TP, whereas the response to Osmopherone® did not differ from the reaction to water. DEET® and ethanol acted as tick repellents and generally evoked positive shifts of TP. We also tested each tick for its questing height (QH) on a glass rod that was at an incline of 75°, and we tested for the presence of pathogens i.e., DNA of Borrelia burgdorferi sp. s.l. and RNA of tick-borne encephalitis virus (TBEV). The degree of response to Osmopherine® positively correlated with the QH. The ticks with the highest values of QH showed a greater prevalence of the tick-borne pathogen Borrelia sp. s.l. compared with the ticks that did not reach the maximum QH. The present results show a correlation between the electrophysiological reaction of the synganglia of ticks and their behavioural responses to different odours.     

The neonicotinoids thiacloprid,imidacloprid, and clothianidin affect the immunocompetence of honey bees (Apis mellifera L.)

A strong immune defense is vital for honey bee health and colony survival. This defense can be weakened by environmental factors that may render honey bees more vulnerable to parasites and pathogens. Honey bees are frequently exposed to neonicotinoid pesticides, which are being discussed as one of the stress factors that may lead to colony failure. We investigated the sublethal effects of the neonicotinoids thiacloprid, imidacloprid, and clothianidin on individual immunity, by studying three major aspects of immunocompetence in worker bees: total hemocyte number, encapsulation response, and antimicrobial activity of the hemolymph. In laboratory experiments, we found a strong impact of all three neonicotinoids. Thiacloprid (24 h oral exposure, 200 μg/l or 2000 μg/l) and imidacloprid (1 μg/l or 10 μg/l) reduced hemocyte density, encapsulation response, and antimicrobial activity even at field realistic concentrations. Clothianidin had an effect on these immune parameters only at higher than field realistic concentrations (50–200 μg/l). These results suggest that neonicotinoids affect the individual immunocompetence of honey bees, possibly leading to an impaired disease resistance capacity.     

Unusual change in activity pattern at cool temperature in a reptile (Sphenodon punctatus)

Animals that can be active both during day and night offer unique opportunities to identify factors that influence activity pattern. By experimental manipulations of temperatures under constant photoperiod, we aimed to determine if emergence, activity and thermoregulatory behaviour of juvenile tuatara (Sphenodon punctatus) varied at different temperatures (20 °C, 12 °C and 5 °C). To help clarify its activity pattern, we compared tuatara with two lizard species endemic of the South Island of New Zealand for which activity pattern is known and clearly defined: the nocturnal common gecko Woodworthia “Otago/Southland” and the diurnal McCann׳s skink Oligosoma maccanni. Tuatara showed similar responses to both species of lizards. Similar to the diurnal skinks, tuatara emerged quickly at 20 °C and 12 °C while nocturnal geckos took more time to emerge. Like nocturnal geckos, tuatara continued to be active at 5 °C, but only during the day. Interestingly, tuatara shifted from diurno-nocturnal activity at 20 °C and 12 °C to being strictly diurnal at 5 °C. We suggest that this temperature-dependent strategy maximises their survival during cold periods.     

Men's revealed preference for their mates' ages

Both young and old men say that they are sexually attracted to young, fertile women, but older men tend to marry older women, including those who are peri- and post-menopausal. We assessed men's freely revealed preference for their mates' age using an unusual marriage phenomenon in South Korea: the practice in which men purchase their brides from developing countries. Presumably, the men's mate choice, at least regarding the brides' age, is unrestricted by women. We analyzed all first marriages reported in 2010–2014 in South Korea and compared men who married Korean brides (N = 1,088,457) with those who purchased their brides (N = 45,528); the age range of grooms and brides was 15–59. While the former exhibited the typical pattern where older men married older women, the latter, whether young or old, always married young, fertile women. This finding is consistent with men's stated preference for young, fertile women in mating and suggests that the typical pattern is generated by women's limiting role in mating.     

Serum profile in preeclampsia and intra-uterine growth restriction revealed by iTRAQ technology

In order to identify new protein markers modified in placental diseases, high-throughput analysis of proteins in the plasma of pregnant women was carried out for normal and pathological pregnancies (Preeclampsia and/or Intra-Uterine Growth Restriction) using iTRAQ technology. We could identify 166 proteins that were modified (p < 0.05) and the technique used allowed the detection of previously undetected factors, such as various members of the SERPINA clade. The modifications of two proteins (C reactive protein and antichymotrypsin, SERPINA3) were validated on individual samples. Complement and coagulation cascades proteins were significantly enriched among modified protein clusters in the case of intra-uterine growth restriction (p < 2.6 · 10^? 11). Several proteins were specifically enriched in isolated preeclampsia and depleted when preeclampsia was complicated by intra-uterine growth restriction. These findings suggest that the growth restricted foeto-placental unit is able to moderate some changes in maternal plasma composition. Overall, the use of iTRAQ technology, for the first time on this subject, enabled us to provide a new list of proteins modified in placental diseases, among which proteins expressed at a low level that were not accessible by other methods.     

The role of vaccines in combating antimicrobial resistance (AMR) bacteria

Most pathogens have developed an intrinsic capacity to thrive by developing resistance to antimicrobial compounds utilized in treatment. Antimicrobial resistance arises when microbial agents such as bacteria, viruses, fungi, and parasites alter their behaviour to make current conventional medicines inefficient. Vaccination is one of the most effective strategies to fight antimicrobial resistance. Vaccines, unlike drugs, are less likely to produce resistance since they are precise to their target illnesses. Vaccines against infectious agents such as Streptococcus pneumoniae and Haemophilus influenzae have already been shown to reduce tolerance to antimicrobial medications; however, vaccines against some antimicrobial-resistant pathogens such as Vibrio cholerae, Salmonella typhi, Escherichia coli, nosocomial infections, and pulmonary and diarrheal disease viruses require more research and development. This paper describes vaccine roles in combatting antimicrobial resistance, quantifies the overall advantages of vaccination as an anti-antimicrobial resistance approach, analyzes existing antimicrobial vaccines and those currently under development, and emphasizes some of the obstacles and prospects of vaccine research and development.     

Genetic,environmental, and neighbor effects on the severity of stereotypies and feather picking in Orange-winged Amazon parrots (Amazona amazonica): An epidemiological study

Stereotypies and psychogenic feather picking represent two distinct forms of abnormal behavior in parrots, with implications for welfare and owner relinquishment. While both behaviors are common in captive parrots, relatively little is known about the factors that may predispose a parrot to their development. To assess the effects of potential social, environmental, and genetic factors, we performed an epidemiological study of a colony of 64 Orange-winged Amazon parrots. We first used mixed model methods to assess the narrow heritability, or genetic determination, of stereotypy, which was −0.08 ± 0.14, and feather picking, which was 1.14 ± 0.27. We then focused our study on one room of 27 birds that had always been housed in the same cage location. We examined the effects of neighbor behavior, number of neighbors, sex, family, age, cage row (beside an aisle or beside a wall), and distance from the door, on each behavior. Stereotypy was negatively correlated with the number of neighbors, but was unaffected by any other factor. In contrast, feather picking was affected by family, was more severe in females, and was progressively more severe in birds housed closer to the door when they had a direct line of sight of the door. Feather picking was spatially clustered in the room, but siblings from particular families were also more likely to be housed as neighbors than were non-siblings. Given the strong effect of family on feather picking and the effect of proximity to the door, these factors together explained the spatial clustering of feather picking. In addition, the feather picking of neighbors was uncorrelated. Thus, there was no evidence for social transmission of feather picking. Our results indicate that cages should be located away from potential stressors, and suggest that there is a potential for breeding against feather picking behavior in parrots. Finally, the markedly different genetic and environmental effects on stereotypies versus feather picking emphasizes that these are two distinct classes of Abnormal Repetitive Behavior in parrots.     

HPTLC and GC–MS finger-printing of two potential multifunctional siddha tailams: Mathan and maha megarajanga tailam

The Siddha system of medicine is an ancient medical lineage that is practiced primarily in the southern part of India. Siddha system of medicine has been in practice for thousands of years with documented evidence dating back to the 6th century BCE. According to siddha system of medicine’s basic fundamental principle, the human body is made up of 96 thathuvam (primary components), which encompass physical, physiological, psychological, and intellectual aspects. Medicine (marunthu) is classified as a wide range of internal and external medicines. The major components of its medical formulations include plant parts, minerals and animal products. Various methods were carried out for the purification process to eliminate the toxins. Choornam, Guligai, Tailam, Parpam, Chendooram, Kattu, Pasai and Poochu are the most common medicines used in Siddha system of medicine for the treatment of various diseases. The pathophysiological classification of diseases is elaborated in detail in the classical Siddha literature. Siddha system of medicine plays an important role in protecting people from diseases such as COVID-19 by providing immune-protecting and immune-boosting medicines in today's world. Mathan tailam and maha megarajanga tailam are the two unique preparations used widely for various skin diseases including chronic wounds and burns. Scientific validation of both medicines will help in understanding their effectiveness against a typical wound condition. In the present study physio-chemical and phytochemical, HPTLC, and GC–MS analyses were carried out and discussed in detail on the multifunctional properties exhibited in the patient communities.     

Design,synthesis, docking and biological evaluation of 4-phenyl-thiazole derivatives as autotaxin (ATX) inhibitors

The autotaxin-lysophophatidic acid (ATX-LPA) signaling pathway is involved in several human diseases such as cancer, autoimmune diseases, inflammatory diseases neurodegenerative diseases and fibrotic diseases. Herein, a series of 4-phenyl-thiazole based compounds was designed and synthesized. Compounds were evaluated for their ATX inhibitory activity using FS-3 and human plasma assays. In the FS-3 assay, compounds 20 and 21 significantly inhibited the ATX at low nanomolar level (IC₅₀ = 2.99 and 2.19 nM, respectively). Inhibitory activity of 21 was found to be slightly better than PF-8380 (IC₅₀ = 2.80 nM), which is one of the most potent ATX inhibitors reported till date. Furthermore, 21 displayed higher potency (IC₅₀ = 14.99 nM) than the first clinical ATX inhibitor, GLPG1690 (IC₅₀ = 242.00 nM) in the human plasma assay. Molecular docking studies were carried out to explore the binding pattern of newly synthesized compounds within active site of ATX. Docking studies suggested the putative binding mode of the novel compounds. Good ATX inhibitory activity of 21 was attributed to the hydrogen bonding interactions with Asn230, Trp275 and active site water molecules; electrostatic interaction with catalytic zinc ion and hydrophobic interactions with amino acids of the hydrophobic pocket.     

Subadult brown bears (Ursus arctos) discriminate between unfamiliar adult male and female anal gland secretion

Olfactory cues have been investigated in social carnivores, many of which use anal/anogenital gland secretion (AGS) for scent marking. However, little is known about how solitary carnivores, such as ursids, use AGS in communication. We hypothesized that subadult (1–3 years) brown bears (Ursus arctos) have the ability to discriminate between unfamiliar adult male and female AGS. Confrontations, especially with adult males, carry high risks for dispersing subadults, so they benefit from the ability to assess potential threats based on olfactory cues, including sex, enabling them to avoid risky encounters. We presented AGS from free-ranging adult brown bears (male = 10, female = 10) to subadult brown bears (male = 13, female = 7) in outdoor zoo experiments, and predicted that subadults would avoid male more than female AGS. Neither male nor female AGS were avoided, but subadults quickly habituated to female AGS. However, male AGS was investigated more intensively and the subadults delayed revisiting it. Subadult tended to take longer to complete 6 visits to male than female AGS, which indicated sexual discrimination. We suggest that subadults that store information for the purpose of scent matching in future encounters may reduce their potential costs of conflict based on their prior assessment of the likely outcome of the encounter.     

Analysis of the factors that affect the distribution and abundance of three Neobuxbaumia species (Cactaceae) that differ in their degree of rarity

We studied three species of columnar cacti in the genus Neobuxbaumia which differ in their degree of rarity: Neobuxbaumia macrocephala (the rarest), Neobuxbaumia tetetzo (intermediate), and Neobuxbaumia mezcalaensis (the most common). To investigate the ecological factors that limit their distribution and abundance, we surveyed 80 localities within the region of Tehuacan-Cuicatlán, in Central Mexico. At each locality we measured several environmental variables, and the density of the Neobuxbaumia populations present. We used a principal component analysis (PCA) to identify the factors that are associated to the presence/absence of each species. Additionally, we carried out multiple regressions between environmental variables and population density to test whether the variation in these variables was related to changes in abundance. The results show that factors significantly affecting the distribution of these species are mean annual temperature, altitude, rainfall, and soil properties such as texture and organic matter content. N. mezcalaensis reaches maximum population densities of 14,740 plants per ha (average density = 3943 plants per ha) and is associated with localities with relatively abundant rainfall. N. tetetzo shows maximum population densities of 14,060 plants per ha (average = 3070 plants per ha), and is associated with sites located at high latitudes and with high phosphorous content in the soil. The rarest species, N. macrocephala, shows maximum densities of 1180 plants per ha (average = 607 plants per ha) and is associated with localities with high soil calcium content. The distribution of this species is limited to sites with specific values of the environmental variables recorded, conferring it a high habitat specificity which accounts for its rarity.     

The use of natural plant volatile compounds for the control of the potato postharvest diseases,black dot,silver scurf and soft rot

Many naturally occurring plant volatile compounds are known for their anti-fungal properties. In this study, acetaldehyde and 2E-hexenal were chosen as prototype volatiles in order to investigate the use of volatile compounds for control of blemish pathogens in fresh-pack potato packaging. Pure cultures of the three main potato blemish pathogens, Pectobacterium atrosepticum (bacterial soft rot), Colletotrichum coccodes (black dot), and Helminthosporium solani (silver scurf), were used in the study. Pathogen cultures were exposed to the pure volatiles that were injected into the atmosphere of sealed jars for 4–8 days at 23 °C. Results showed that 2E-hexenal was the most effective of the two volatiles with 5 μL/L providing complete inhibition of growth for all three pathogens in vitro. Cytological studies showed that a concentration of 2.5 μL/L of 2E-hexenal was capable of inhibiting germination in both fungal pathogens. These results suggest that the primary mode of action of 2E-hexenal was inhibiting germination for fungi and suppressing bacterial growth. The quantities required to achieve pathogen inhibition are extremely low. This study suggests that these volatiles may be used to effectively manage potato postharvest blemish diseases in storage.     

Long-term adaptations of a migratory bird (Little Tern Sternula albifrons) to quasi-natural flooding disturbance

Population size of migratory birds responds to various types of environmental factors, which affect different stages of bird population. In the current study, we analyzed a long-term avifauna monitoring database to investigate population changes in the migratory bird Little Tern, Sternula albifrons, with respect to a quasi-natural disturbance, flooding, induced by a regional characteristic climate pattern, the Korean Monsoon (KM), in the Nakdong River Estuary of South Korea. We scrutinized the time-delayed influence by means of wavelet transformation and year-to-year comparison. Little Tern individuals started to grow in April, and reached its maximum generally in May or June, and an abrupt decrease of individual number was observed after KM occurred. Sequential time-series analysis based on wavelet transformation revealed that the changing pattern of the population size of Little Tern in the estuary was linked to the previous year's flooding (a 9- to 10-month delay), which is regarded as the time difference between Little Tern breeding season and previous KM period. Stronger flooding waters during KM season expelled comparably more individuals of Little Tern from the estuary (r² = 0.595; p < 0.05; n = 9), and the more the individuals left, the smaller the bird arrived at the estuary in the next year. Further examination revealed that earlier initiation and longer duration of KM in year_t − 1 negatively affected the newly arriving Little Tern individuals in the current year (i.e., year_t; r² = 0.809 for impact of KM onset, r² = 0.909 for impact of KM duration; n = 10, respectively; p < 0.005). The Little Tern population gradually increased when summer flooding was not strong in the previous successive years, from which we concluded that the population of the migratory bird Little Tern tends to adapt to quasi-natural disturbance (flooding) to maintain their population size.     

How do reactive oxygen species and calcium trigger mitochondrial membrane permeabilisation?

BackgroundMitochondrial membrane permeabilisation (MMP) is classically considered as a point of no return in several forms of cell death and is involved in numerous diseases such as cancer, neurodegenerative disorders or ischemia/reperfusion injuries. Many studies established that reactive oxygen species (ROS) and Ca^2 + were the prominent inducers of MMP. However, the mechanisms connecting ROS and Ca^2 + to the players of MMP are still a matter of debate.Scope of reviewThe aim of this review is to summarise the various studies related to the mechanisms of ROS- and Ca^2 +-induced MMP. Several lines of evidence suggest that ROS and Ca^2 + cooperate to induce MMP but the molecular details of the ROS–Ca^2 +-MMP network remain controversial. We then discuss recent data depicting this topic.Major conclusionsCytotoxic stimuli may be transduced within the cell by ROS and Ca^2 + increases. In most models, Ca^2 + and ROS can cooperate to induce MMP. Moreover, several data suggest that MMP increases mitochondrial Ca^2 + and ROS which therefore amplify the cytotoxic signal. Intriguingly, many reports have identified players of MMP as direct ROS targets. On the contrary, direct targets of Ca^2 + remain elusive. At the same time, the mechanisms by which mitochondrial Ca^2 + overload induces ROS generation are well documented. Upon these observations, we hypothesise that Ca^2 + cannot directly induce MMP and requires ROS production as a mandatory step.General significanceGiven the importance of Ca^2 +- and ROS-induced MMP in diseases, we expect that a better understanding of this process will lead to the development of novel therapies.     

The reliability of a composite biodiversity indicator in predicting bird species richness at different spatial scales

Several biodiversity features can be linked to landscape heterogeneity, that, in turn, can be informative for management and conservation purposes. Usually, the more the landscape is complex the more the biodiversity increases. Biodiversity indicators can be a useful tool to assess biodiversity status, in function of landscape heterogeneity. In this study, we developed a biodiversity indicator, based on Shannon diversity index and built from distribution maps of protected species. With such an approach, we seek to evaluate the feasibility of using a combination of target species as a surrogate for assessing the status of the whole bird community. Our approach was spread over multiple spatial scales, to determine which was the most informative. We selected four species protected by European regulation and generated a presence-absence map from species distribution modelling. We, therefore, used the FRAGSTATS biodiversity metric to calculate Shannon index for the overlapped presence-absence maps, at two spatial scales (500 m and 1000 m). Then, the relationships with the whole community was assessed through generalised least square models, at the spatial scale of 4 ha, 9 ha and 25 ha. Results showed that the higher rate of variability of community was explained by the biodiversity indicator at 1000 m scale. Indeed, the more informative spatial scale for the whole bird community was 9 ha. In addition, a pattern emerged about the relationships between biodiversity indicator and community richness, that is worth of further research. Our study demonstrates that the usefulness of surrogate species for biodiversity and community assessment can become clear only at a certain spatial scales. Indeed, they can be highly predictive of the whole community, and highly informative for conservation planning. Moreover, their use can optimize biodiversity monitoring and conservation, focusing on a small number of noteworthy species.     

Skeletal muscle pericyte subtypes differ in their differentiation potential

Neural progenitor cells have been proposed as a therapy for central nervous system disorders, including neurodegenerative diseases and trauma injuries, however their accessibility is a major limitation. We recently isolated Tuj1 + cells from skeletal muscle culture of Nestin–GFP transgenic mice however whether they form functional neurons in the brain is not yet known. Additionally, their isolation from nontransgenic species and identification of their ancestors is unknown. This gap of knowledge precludes us from studying their role as a valuable alternative to neural progenitors. Here, we identified two pericyte subtypes, type-1 and type-2, using a double transgenic Nestin–GFP/NG2–DsRed mouse and demonstrated that Nestin–GFP +/Tuj1 + cells derive from type-2 Nestin–GFP +/NG2–DsRed +/CD146 + pericytes located in the skeletal muscle interstitium. These cells are bipotential as they generate either Tuj1 + cells when cultured with muscle cells or become “classical” α-SMA + pericytes when cultured alone. In contrast, type-1 Nestin–GFP ?/NG2–DsRed +/CD146 + pericytes generate α-SMA + pericytes but not Tuj1 + cells. Interestingly, type-2 pericyte derived Tuj1 + cells retain some pericytic markers (CD146 +/PDGFRβ +/NG2 +). Given the potential application of Nestin–GFP +/NG2–DsRed +/Tuj1 + cells for cell therapy, we found a surface marker, the nerve growth factor receptor, which is expressed exclusively in these cells and can be used to identify and isolate them from mixed cell populations in nontransgenic species for clinical purposes.     

Isobutanol production at elevated temperatures in thermophilic Geobacillus thermoglucosidasius

The potential advantages of biological production of chemicals or fuels from biomass at high temperatures include reduced enzyme loading for cellulose degradation, decreased chance of contamination, and lower product separation cost. In general, high temperature production of compounds that are not native to the thermophilic hosts is limited by enzyme stability and the lack of suitable expression systems. Further complications can arise when the pathway includes a volatile intermediate. Here we report the engineering of Geobacillus thermoglucosidasius to produce isobutanol at 50 °C. We prospected various enzymes in the isobutanol synthesis pathway and characterized their thermostabilities. We also constructed an expression system based on the lactate dehydrogenase promoter from Geobacillus thermodenitrificans. With the best enzyme combination and the expression system, 3.3 g/l of isobutanol was produced from glucose and 0.6 g/l of isobutanol from cellobiose in G. thermoglucosidasius within 48 h at 50 °C. This is the first demonstration of isobutanol production in recombinant bacteria at an elevated temperature.     

Design,synthesis, in vitro evaluation and preliminary SAR studies of N-(2-(heteroaryloxy)propyl)phenothiazines against Rhipicephalus microplus cattle tick

A family of 15 N-substituted phenothiazines was designed, synthesized and their acaricidal activity against Rhipicephalus microplus was determined in vitro. The synthetic methodology is simple and can be employed in multigram scale. The rationale for the structure-based design of these compounds is the potential for azines and phenothiazine to engage in π–π interactions; these fragments, joined together by a short, flexible alkoxide linker, structurally resemble phenothiazine-based cholinesterase inhibitors, while their weak basicity implies a neutral active form, rather than a cationic one, thus facilitating penetration of the cuticle of ticks. One compound displayed excellent acaricidal activity (LD₅₀ = 0.58 μg/mL). Preliminary SAR analysis suggests that the activity is influenced by the presence of a weakly basic nitrogen atom, as well as the substitution pattern within the heterocycles.