In the present study, we have investigated the role of antimalarial drug halofantrine (HF) in inducing the sterile protection against challenges with sporozoites of the live infectious Plasmodium yoelii (Killick-Kendrick, 1967) in Swiss mice malaria model. We observed that during the first to third sequential sporozoite inoculation cycles, blood-stage patency remains the same in the control and chemoprophylaxis under HF drug cover (CPS-HF) groups. However, a delayed blood-stage infection was observed during the fourth and fifth sporozoite challenges and complete sterile protection was produced following the sixth sporozoite challenge in CPS-HF mice. We also noticed a steady decline in liver stage parasite load after 3th to 6th sporozoite challenge cycle in CPS-HF mice. CPS-HF immunisation results in a significant up-regulation of pro-inflammatory cytokines (IFN-γ, TNF-α, IL-12 and iNOS) and down-regulation of anti-inflammatory cytokines (IL-10 and TGF-β) mRNA expression in hepatic mononuclear cells (HMNC) and spleen cells in the immunised CPS-HF mice (after 6th sporozoite challenge) compared to control. Overall, our study suggests that the repetitive sporozoite inoculation under HF drug treatment develops a strong immune response that confers protection against subsequent challenges with sporozoites of P. yoelii.
Perinatal hypoxia is still one of the greatest threats to the
newborn child, even in developed countries. However, there is
a lack of works which summarize up-to-date information about
that huge topic. Our review covers a broader spectrum of recent
results from studies on mechanisms leading to hypoxia-induced
injury. It also resumes possible primary causes and observed
behavioral outcomes of perinatal hypoxia. In this review, we
recognize two types of hypoxia, according to the localization of
its primary cause: environmental and placental. Later we analyze
possible pathways of prenatal hypoxia-induced injury including
gene expression changes, glutaminergic excitatory damage (and
a role of NMDA receptors in it), oxidative stress with ROS and
RNS production, inflammation and apoptosis. Moreover, we focus
on the impact of these pathophysiological changes on the
structure and development of the brain, especially on its regions:
corpus striatum and hippocampus. These brain changes of the
offspring lead to impairments in their postnatal growth and
sensorimotor development, and in their motor functions, activity,
emotionality and learning ability in adulthood. Later we compare
various animal models used to investigate the impact of prenatal
and postnatal injury (hypoxic, ischemic or combinatory) on living
organisms, and show their advantages and limitations.
The healthy development of the fetus depends on the exact course of pregnancy and delivery. Therefore, prenatal hypoxia remains between the greatest threats to the developing fetus. Our study aimed to assess the impact of prenatal hypoxia on postnatal development and behavior of the rats, whose mothers were exposed to hypoxia (10.5 % O2) during a critical period of brain development on GD20 for 12 h. This prenatal insult resulted in a delay of sensorimotor development of hypoxic pups compared to the control group. Hypoxic pups also had lowered postnatal weight which in males persisted up to adulthood. In adulthood, hypoxic males showed anxiety-like behavior in the OF, higher sucrose preference, and lower levels of grimace scale (reflecting the degree of negative emotions) in the immobilization chamber compared to the control group. Moreover, hypoxic animals showed hyperactivity in EPM and LD tests, and hypoxic females had reduced sociability compared to the control group. In conclusion, our results indicate a possible relationship between prenatal hypoxia and changes in sociability, activity, and impaired emotion regulation in ADHD, ASD, or anxiety disorders. The fact that changes in observed parameters are manifested mostly in males confirms that male sex is more sensitive to prenatal insults.
This paper explores the impacts of reconfiguration and leaf morphology on the flow downstream of a flexible foliated plant. 3D acoustic Doppler velocimetry and particle image velocimetry were used to experimentally investigate the hydrodynamic interaction between a foliated plant and the flow, testing two plants with different leaves morphology under different bulk flow velocities. The model vegetation was representative of riparian vegetation species in terms of plants hydrodynamic behavior and leaf to stem area ratio. To explore the effects of the seasonal variability of vegetation on the flow structure, leafless conditions were tested. Reconfiguration resulted in a decrease of the frontal projected area of the plants up to the 80% relative to the undeformed value. Such changes in plant frontal area markedly affected the spatial distributions of mean velocity and turbulence intensities, altering the local exchanges of momentum. At increasing reconfiguration, the different plant morphology influenced the mean and turbulent wake width. The leafless stem exhibited a rigid behavior, with the flow in the wake being comparable to that downstream of a rigid cylinder. The study revealed that the flexibility-induced reconfiguration of plants can markedly affect the local distribution of flow properties in the wake, potentially affecting transport processes at the scale of the plant and its subparts.
Abandonment of agricultural lands in recent decades is occurring mainly in Europe, North America and Oceania, and changing the fate of landscapes as the ecosystem recovers during fallow stage. The objective of this study was to find the impact of secondary succession in abandoned fields on some parameters of acidic sandy soils in the Borská nížina lowland (southwestern Slovakia). We investigated soil chemical (pH and soil organic carbon content), hydrophysical (water sorptivity, and hydraulic conductivity), and water repellency (water drop penetration time, water repellency cessation time, repellency index, and modified repellency index) parameters, as well as the ethanol sorptivity of the studied soils. Both the hydrophysical and chemical parameters decreased significantly during abandonment of the three investigated agricultural fields. On the other hand, the water repellency parameters increased significantly, but the ethanol sorptivity did not change during abandonment. As the ethanol sorptivity depends mainly on soil pore size, the last finding could mean that the pore size of acidic sandy soils did not change during succession.
The Gram-negative, obligate intracellular tick-transmitted pathogen Anaplasma phagocytophilum can cause acute febrile diseases in humans and domestic animals. The expansion of the tick Ixodes ricinus (Linnaeus, 1758) in northern Europe due to climate change is of serious concern for animal and human health. The aim of the present study was to investigate the impact of A. phagocytophilum infection in moose Alces alces (Linnaeus) calves by evaluating the carcass weights of infected and non-infected animals and examining animal tissues samples for co-infections with either species of Babesia Starcovici, 1893 or bacteria of the genus Bartonella. The carcasses of 68 free-ranging moose calves were weighed by hunters during the hunting seasons from 2014 to 2017 in two regions in southern Norway and spleen samples were collected. Anaplasma phagocytophilum was detected in moose sampled from locations infected with ticks with a prevalence of 82% (n = 46). The carcass weights of A. phagocytophilum-infected calves (n = 46) and non-infected (n = 22) calves were compared. Although the average weight of infected calves (45.6 kg) was lower than that of non-infected calves (46.5 kg), the difference was not statistically significant. Three different variants of the bacterium 16S rRNA gene were identified. The average weight of animals infected with variant I was 49.9 kg, whereas that of animals infected with variant III was 42.0 kg, but the difference was not statistically significant (p = 0.077). Co-infections of A. phagocytophilum with Bartonella spp. or with Babesia spp. were found in 20 and two calves, respectively. A triple infection was found in two calves. Sequence analysis of the 18S rRNA gene of Babesia-positive samples revealed the presence of Babesia cf. odocoilei (Emerson et Wright, 1970). Strains of Bartonella closely related to Bartonella bovis (Bermond, Boulouis, Heller, Laere, Monteil, Chomel, Sander, Dehio et Piemont, 2002) were identified based on phylogenetic analysis of the gltA and rpoB genes. The loss of body mass in moose calves in the tick-infected site was probably influenced by multiple factors.
Acid rain is a serious environmental problem and has obvious impacts on the growth, reproduction, and photosynthesis of terrestrial plants. Ulva prolifera, a main blooming species of green tides, was studied on its physiological response to acid rain. The photosynthetic parameters were determined under different conditions (salinity: 1, 10, 30‰; pH: 3.0, 3.5, 4.5; duration: 0.5, 1.0, 2.0 h) followed by 24-h recovering under natural conditions. Results showed 1-h treatment with pH 3.5 caused 50-70% reduction in the maximal quantum yield of PSII photochemistry (Fv/Fm) and effective quantum yield of PSII photochemistry (ФPSII) at normal salinity but when the low pH was combined with a salinity of 10‰ or lower, PSII activity was almost completely inhibited. Moreover, the low salinity (1‰ and 10‰) reduced the degree of photoprotection under low pH (3.5) conditions. Finally, we speculated if the pH of acid rain ≤ 3.5, with 1‰ salinity and 2-h rainfall time, the amount of U. prolifera and the scale of green tides would decrease.
Animals, including human beings, tend to respond more strongly to stimuli that are associated with the highest relative rewards. This applies not only to food rewards but also to reproductive success. In the present review article this issue is discussed for insects in connection with intersexual communication and flower-visiting behaviour. Implications of the preference for supernormal visual releasing stimuli are examined from a sensory and evolutionary perspective, including a consideration of the choice of potential mates and recognition of the most rewarding flowers., Karl Kral., and Obsahuje bibliografii
We aimed to assess the importance of anthropogenic roosts for bats hibernating in the Roztocze National Park (south-east Poland), based on data collected from 2009 to 2021. We recorded 310 bats from nine species hibernating in 27 artificial underground roosts (root cellars and basements of buildings). The most abundant and constantly recorded species were Plecotus auritus (60.2%), Barbastella barbastellus (20.6%) and Myotis nattereri (14.2%), while the remaining species can be considered of secondary importance; Plecotus austriacus (1.3%), Myotis myotis (1.9%), Myotis bechsteinii (1.3%), M. daubentonii (0.3%), Myotis mystacinus sensu lato (0.3%) and Eptesicus serotinus (1.3%). An estimate of the Shannon diversity index gave a mean H = 0.947 (SD = 0.247, range 0.377-1.352), while the Buzas and Gibson´s evenness index gave values of E = 0.695 (SD = 0.125, range 0.551-0.940). The Shannon index was positively correlated with the number of recorded bats and varied substantially among years.
Wheat yellow-green mutant Jimai5265yg has a more efficient photosynthetic system and higher productivity than its wild type under N-deficient conditions. To understand the relationship between photosynthetic properties and the grain yield, we conducted a field experiment under different N application levels. Compared to wild type, the Jimai5265yg flag leaves had higher mesophyll conductance, photosynthetic N-use efficiency, and photorespiration in the field without N application. Chlorophyll a fluorescence analysis showed that PSII was more sensitive to photoinhibition due to lower nonphotochemical quenching (NPQ) and higher nonregulated heat dissipation. In N-deficient condition, the PSI acceptor side of Jimai5265yg was less reduced. We proposed that the photoinhibited PSII protected PSI from over-reduction through downregulation of electron transport. PCA analysis also indicated that PSI photoprotection and electron transport regulation were closely associated with grain yield. Our results suggested that the photoprotection mechanism of PSI independent of NPQ was critical for crop productivity.