Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics.

Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.

Humeral fracture in arm wrestling: bone morphology as a permanent risk factor. Indications for safety measures in arm wrestling.

BACKGROUND: Arm wrestling has been recognized as a popular and potentially dangerous competition. Reports on injuries related to arm wrestling are increasing. The most important of these injuries are humeral shaft fractures. The generally accepted theory states that the shoulder joint is actively internally rotated against the opponent while the elbow is fixed in flexion resulting in enormous violent torque forces across the humeral shaft. METHODS: The reported fracture morphology seems similar so we theorized that the basis of this fracture type is the bone structure. There is no experimental model of the arm wrestling fracture other than a virtual one. We assess morphology of the humeral bone by means of the bone cutting procedures and to verify the theory that the structure of humeral bone is a basis of the arm-wrestling fracture by means of newly developed model on human bones. RESULTS: Results of the study suggest that the humeral shaft fracture morphology during arm wrestling is based on the spiral structure of the bone combined with the direction of the revolving, rotational force during the match. CONCLUSION: The safety rules of the arm-wrestling match based on results of our experimental study and the literature metaanalysis are also formulate.

Effect of reduced atmospheric pressure on growth and quality of two lettuce cultivars.

Future space missions will likely include plants to provide fresh foods and bioregenerative life support capabilities. Current spacecraft such as the International Space Station (ISS) operate at 1 atm (101 kPa) pressure, but future missions will likely use reduced pressures to minimize gas leakage and facilitate rapid egress (space walks). Plants for these missions must be able to tolerate and grow reliably at these reduced pressures. We grew two lettuce cultivars, 'Flandria' a green bibb-type and 'Outredgeous,' a red, loose-leaf type, under three pressures: 96 kPa (ambient control), 67 kPa (2/3 atm), and 33 kPa (1/3 atm) for 21 days in rockwool using recirculating nutrient film technique hydroponics. Each treatment was repeated three times using a different hypobaric chamber each time. A daily light integral of 17.2 Moles Photosynthetically Active Radiation per day was provided with metal halide lamps set to deliver 300 µmol m-2s -1 photosynthetic photon flux (PPF) for a 16 h photoperiod at 22 °C. Oxygen was maintained at 21 kPa (equal to 21% at 1 atm) and CO2 at 0.12 kPa (equal to 1200 ppm at 1 atm). Leaf area for 'Outredgeous' was reduced 20% and 38% at 67 kPa and 33 kPa respectively; shoot fresh mass was reduced 22% and 41% at 67 kPa and 33 kPa respectively when compared to control plants at 96 kPa. These trends were not statistically significant at P ≥ 0.05. Leaf area for 'Flandria' showed no difference between 96 and 67 kPa but was reduced 31% at 33 kPa; shoot fresh mass was reduced 6% and 27% at 66 kPa and 33 kPa respectively compared to 96 kPa. There were 10% and 25% increases in anthocyanin concentration at 66 kPa and 33 kPa compared to 96 kPa, potentially increasing the bioprotective capacity of the plant. Previous studies with other cultivars of lettuce showed slight change in growth across this range of pressures, suggesting responses may vary among genotypes, hypobaric exposure treatments, and / or environmental conditions. Collectively, the findings suggest further testing is needed to understand the effects of atmospheric pressure on plant growth.

Prenatal acrylamide exposure results in time-dependent changes in liver function and basal hematological, and oxidative parameters in weaned Wistar rats.

Acrylamide (ACR) is a toxic compound commonly found in fried, baked and heat-processed starchy foods. The current study investigated the time-dependent effects of maternal exposure to non-toxic ACR doses on the oxidative stress, liver function, and basal blood morphology of the rat offspring. Pregnant, Wistar rats were randomly divided into the control group or the groups administrated with ACR (3 mg/kg b.w./day): long exposure for 15 days, medium exposure for 10 days and short exposure for 5 days during pregnancy. Body mass, blood morphology and hematology, serum concentrations of growth hormone, IGF-1, TNF-α, IL-1ß, IL-6 and insulin, liver histomorphometry, liver activity of beclin1, LC2B and caspase3, markers of oxidative stress and the activity of antioxidative enzymes in blood serum and the liver were measured in offspring at weaning (postnatal day 21). Even short prenatal exposure to ACR led to oxidative stress and resulted in changes in liver histomorphometry and upregulation of autophagy/apoptosis. However, the most significant changes were observed following the long period of ACR exposure. This study has shown for the first time that ACR is responsible for changes in body mass in a time-dependent manner, which could lead to more serious illnesses like overweight and diabetes later in life.

Analysis of mechanical properties of bones and tendons shows that modern hybrid rye can be introduced to corn-wheat based diet in broiler chickens as an alternative energy source irrespective of xylanase supplementation.

This study focused on analyzing the effects of inclusion of modern hybrid rye to corn-wheat diet on mechanical properties of bones and tendons. A total of 224 broiler chickens were fed a diet without rye inclusion or a diet containing 15% of hybrid rye cv. Brasetto. The diets were either unsupplemented or supplemented with xylanase (minimum activity 1000 FXU/g, dose 200 mg/kg of feed). Each dietary group consisted of 56 birds. On day 42, selected chickens (n = 7 from each group) were slaughtered. Tibia were analyzed for mineralization, geometry, and biomechanical characteristics of bone mid-diaphysis. The mechanical properties of digital flexor III tendon were also assessed. Bone mineral density and bone ash percentage did not differ when both diets were given without xylanase. Enzyme supplementation increased bone mineral density (P < 0.01) in both dietary groups, whereas bone ash percentage (P < 0.01) increased only for corn-wheat diet. Rye inclusion had no effect on bone mid-shaft geometrical traits related to tibia weight-bearing capacity (cross-sectional area, cortical index, and mean relative wall thickness). Performed bending test showed no effect of hybrid rye inclusion on bone mechanical endurance. When xylanase was supplemented, bone length (P < 0.01) and weight (P < 0.05) decreased, whereas yield load (P < 0.01), stiffness (P < 0.05), Young modulus (P < 0.05), elastics stress (P < 0.01), and ultimate stress (P < 0.01) increased, irrespective of rye presence. The tendon tensile strain test showed that in corn-wheat diet enzyme supplementation positively influenced rupture force (P < 0.05) and tendon stiffness (P < 0.01). Xylanase supplementation increased the value of energy required to tendon rupture, irrespective of rye inclusion (P < 0.05). Study showed that modern hybrid rye varieties can be introduced to corn-wheat diets of broiler chickens in the aspect of animal welfare related to the development and homeostasis of musculoskeletal system, irrespective of xylanase supplementation. The enzyme addition positively affected biomechanical properties of bones and tendons.

The influence of dexamethasone administered prenatally on cartilage of newborn spiny mouse (Acomys cahirinus) offspring.

Considering the negative effects of glucocorticoid treatment, especially during fetal development it is important to investigate effectors decreasing such disadvantages. The aim of this study was to investigate the effect of prenatally administered dexamethasone (Dex), a synthetic glucocorticoid, on the histomorphometry of the femur in the offspring of spiny mice. The study was performed on 24 pregnant spiny mice. The time of the experiment included the prenatal period between the 20th day of gestation until birth (pregnancy lasts on average of 36-38 days). The mice from the experimental group received dexamethasone per os in a dose of 125 mg/kg birth weight daily. At the end, the newborns from the experimental and control group were weighted and euthanized. Maternal Dex treatment resulted in a 17% decrease in birth weight in newborns. Dex administration significantly reduced the thickness of the hypertrophy zone of the growth plate by 34% and total thickness by 8,7%. In addition, Dex decreased the number of cells in the articular cartilage by 27% and significantly decreased their diameter by 5%. Dex also affected the structure and spatial distribution of thick and thin collagen fibers, lowering the proportion of thin fibers compared with the control group. Moreover, Dex treatment considerably lowered the amount of proteoglycans in articular and growth cartilages. Exposure to glucocorticoids in pregnant spiny mice affects cartilage development by accelerating maturity of collagen fibers and growth plate, presumably along with further disruption of longitudinal growth of long bones.

C-terminally shortened alamethicin on templates: influence of the linkers on conductances.

In order to test the influence of chemical modifications designed to allow covalent coupling of channel-forming peptide motifs into variable sized oligomers, a series of alamethicin derivatives was prepared. The building block encompassing the N-terminal 1-17 residues of alamethicin behaved normally in the conductance assay on planar lipid bilayers, albeit at higher concentration and with a slightly reduced voltage-dependence. A linker Ac-K-OCH(2)C(6)H(4)CH(3)p attached via the epsilon amino group of lysine to the C-terminus of alamethicin(1-17) increased membrane affinity. The latter was further enhanced in a dimer and a tetramer in which alamethicin(1-17) chains were tethered to di- or tetra-lysine linkers, respectively, but macroscopic current-voltage curves displayed much reduced voltage-dependencies and reversed hysteresis. An usual behaviour with high voltage-dependence was restored with the modified dimer of alamethicin(1-17) in which alanine separated the two consecutive lysine residues in the linker. Of special interest was the development of a 'negative resistance' branch in macroscopic current-voltage curves for low concentrations of this dimer with the more flexible linker. Single channel events displayed only one single open state with fast kinetics and whose conductance matches that of the alamethicin heptamer or octamer.

Delayed response learning to auditory stimuli is impaired in cage-reared cats.

Four normal and eight cage-reared cats were used. Four of the cage-reared cats were visually deprived in the first 6 months of life. The cats were trained on a three-choice delayed response task to auditory stimuli. All normal cats mastered a 1-min delay and two cats even a 6-min delay. In contrast, two cage-reared cats failed to cope even with a 5-s delay, four cats with a 15-s delay and the remaining two cats with a 1-min delay. No significant difference was found between the non-deprived and the deprived cage-reared cats. The deficits was analogous to that shown by cage-reared cats during delayed response, visual learning. Thus, cage-rearing strongly impairs delayed responding to at least two different sensory modalities.

Habituation of ocular following reflex requires corpus callosum for interhemispheric transfer.

In cats, unanesthetized following transection of the brainstem at a level precluding painful sensation, and limiting ocular motility to a vertically oriented course (the pretrigeminal preparation), habituation of the orienting reflex, consisting of ocular fixation and smooth pursuit, readily transferred between moving visual stimuli directed first at one and then the other cerebral hemisphere. Under the same conditions, when the corpus callosum had been transected 2 weeks prior to the habituation, interhemispheric transfer was absent. Thus, despite substantial brainstem involvement and bilateral coordination of ocular motility the neocortex plays an essential role in this habituation, just as it does in the interhemispheric transfer of visual discrimination learning. This suggests that habituation is a fundamental form of learning in the mammalian forebrain.

Food conditioning is impaired in cats deprived of the taste of food in early life.

Cats were fed by stomach tube during the first 75 days of their life. Thus, they were deprived of the taste of food and the food reward. The cats were then trained to find food behind the gate. They acquired this simple response very slowly and during the first weeks of training they often refused to eat the food reward. Moreover, they extinguished the response poorly. We conclude that the deprived cats did not originally perceive the food reward as attractive, but they were able to learn this, and they were poorly able to form both excitatory and inhibitory food conditioned connections.

The contralateral impairment of the orienting ocular-following reflex after lesions of the lateral suprasylvian cortex in cats.

The cortex of the middle suprasylvian sulcus was removed unilaterally in cats with brain stem transected at the pretrigeminal level. The vertical following reflex was evoked by a slit of light (1 degree x 4 degrees) moving along the vertical meridian or parallel to it up to 40 degrees in the left or right hemifield. The reflexes from the contralateral hemified were greatly reduced. This contrasts with previous reports with perimetry test where authors made smaller lesions.

Effects of different intrastimulus interval on learning of the Konorski short-term memory test in dogs.

A differentiation of instrumental responses to auditory location stimuli using the Konorski Test was investigated. Each stimulus consisted of two components separated by intrastimulus interval. The components were click series presented from four loudspeakers situated in front of the animal, on horizontal and vertical axes. Each correct response, performed to the second component of positive stimulus, was rewarded by food. Responses to negative stimuli were not reinforced. Solving the test was possible by comparing the memory trace of the first component location, with location of actually presented second component. Two groups of dogs were trained. In one group positive and negative stimuli were presented, in which intrastimulus interval lasted 1 s. In the other group, differentiation training included stimuli with intrastimulus interval lasting 3 s. Unexpectedly, the first group was unable to reach differentiation criterion, whereas the second group reached criterion without difficulty. The effect of reaching the criterion with longer and not shorter interval between stimulus components, may be specifically related to location cues as opposed to reported earlier auditory quality stimuli.

Delayed response learning to visual stimuli in cats.

Six normally reared cats were trained on a three-choice delayed response task to visual stimuli. All cats mastered 1 min delay, three cats 2 min delay and one cat 6 min delay. Learning was much better than in previously studied cats reared in laboratory cages. It was comparable to that known for auditory stimuli in normally reared cats.

Behavioral recovery on a spatial variant of the Konorski test following prefrontal damage in dogs.

Two groups of naive dogs were trained on a spatial variant of the Konorski Test, in which pairs of successively presented auditory location cues were differentiated in a conditioning procedure. Instrumental leg flexion to positive stimuli was reinforced by food. Combinations of four different location cues were used as compound conditioned stimuli (CS). In group AA a positive CS involved two identical, successively presented location cues, Sx-Sx, separated by an interval of 5 s, whereas the negative CS was formed by two different successive location, cues, Sx-Sy, with the same intercomponent interval. In group AB positive and negative combinations of location cues were reversed: Sx-Sy combinations were positive, while Sx-Sx were negative. Solving the task required a comparison of the second CS component with the memory trace left by the first component of CS. The two groups did not differ in reaching the preoperative criterion, but the response time was significantly shorter in the AA group. Prefrontal proreal lesion produced a significant but transient impairment of performance in both groups. The third group, trained on a simple differentiation task with single location cues, was completely unimpaired.

Lack of projections from medial geniculate body to suprasylvian cortex in cat: a study with horseradish peroxidase.

Because both electrophysiological and behavioral methods have implicated the suprasylvian cortex of cat in audition, its afferents were studied using retrograde transport of horseradish peroxidase. The bulk-filling method was used to maximize the likelihood that virtually all afferents to the area would be labeled. Despite the vivid retrograde labeling of many thalamic cells with this procedure, no direct auditory projections to the suprasylvian cortex could be found in the thalamus (i.e. in medial geniculate body or in the dorsolateral part of the posterior nucleus). Furthermore, very few cells were labeled in the primary auditory cortex of the nearby ectosylvian gyrus. The source of afferents to the suprasylvian cortex originate mostly from the pulvinar-lateral posterior complex and to a lesser extent from ventral lateral and ventral anterior nuclei of the thalamus.

Auditory quality cues are more effective than auditory location cues in a R--no R (go--no go) differentiation: the extension of the rule to primitive mammals (American opossum, Didelphis virginiana).

Discrimination learning of instrumental responses to auditory compound stimuli was investigated in opossums using the R-no R (go-no go) differentiation. Each compound stimulus consisted of two factors: quality and location. Each correct response performed to the conditioned positive, or "safe" stimulus, was rewarded by food and never punished. Each incorrect response performed to the conditioned negative, or "warning" stimulus, was punished by an electric shock. In subsequent testing, each opossum proved to use only the quality cues to solve the task even though later testing showed them capable of using the location cues. Thus, the rule discovered in higher mammals, that the efficacy of auditory stimuli in differentiation depends on the perceptual ability of the animal as well as the type of the behavioral response with which the animal is confronted, may be extended to neurologically primitive mammals and also to a joint conditioned approach-avoidance method.

Electrical activity of the acutely isolated pons in cats.

The cat's pons was isolated by two brainstem transections, at the junction of medulla and pons and at the junction of pons and midbrain. In the deafferented pons the EEG activity was virtually absent, whereas the spatial density of active units and the rate of their spontaneous spike activity were at a high level. In the pons of control preparations with brainstem transected only at the ponto-midbrain junction the EEG activity was present, while the single-unit activity was such as in the isolated pons. The electrical activity of the isolated pons was similar to that previously described in the cat's isolated midbrain. The discrepancy between EEG and single-unit activity suggests that in the deafferented pons or midbrain many neurones are asynchronously autoactive. Also, these results show that a flat EEG record is not necessarily a sign of absence of the neural activity and neural death.

Sealed environment chamber for canopy light interception and trace hydrocarbon analyses.

Two sealed chambers were constructed, each measuring approximately 4.5 m x 3 m x 2.5 m (LxWxH). Heat exchangers and air handling components were integrated within the sealed environment. Construction materials were chosen to minimize off-gassing and oxidation. Acceptable materials included stainless steel, Teflon (TM), glass and Heresite (TM) or baked enamel coated metal parts. The glass-topped chambers have externally mounted microwave powered light sources providing minimum PAR at canopy level of 1000 micrometers m-2 s-1. Major gases (CO2, O2) were monitored. Other environmental variables relevant to plant production (humidity, temperature, nutrient solution) were monitored and controlled continuously. Typical environment control capability and system specifications are presented. The facility is described as a venue ideally suited to address specific research objectives in plant canopy light interception, such as the roles of novel microwave powered overhead and inner-canopy light sources for dense plant canopies. In addition, control of recycled hydroponic nutrient solutions and analysis of trace atmospheric hydrocarbons in the context of sealed environment life support can be concurrently monitored.

EEG activity in cat's isolated brainstem.

Midbrain and pons were isolated together by two brainstem transections, at the junctions between midbrain and forebrain on one hand and the medulla and pons on the other hand. Low-voltage, high-frequency and high-voltage, low-frequency EEG activity were present in the isolated brainstem. This is in contrast to previous findings, showing that in the midbrain and pons separately isolated the EEG activity was greatly depressed, although accompanied by brisk single-unit spike activity. Thus, neural connections between pons and midbrain may lead to synchronization of single-unit activity.

Visual neglect in pretrigeminal cats with lateral suprasylvian lesions.

Eleven cats with brain stem transected at the pretrigeminal level were used. The cortex of the middle suprasylvian sulcus was removed on the left side. The vertical following reflex was evoked by a slit of light (1 degree x 4 degrees) or a black bar (1 degree x 1 degree x 4 degrees) moving along the vertical meridian or parallel to it out to 40 degrees in the left or right hemifield. In all cats the following reflexes to the contralesional hemifield were low or absent. A corresponding suprasylvian lesion was made subsequently on the right side. In 6 cats the reflexes to both hemifields were absent or low. In contrast, surprisingly in 5 cats the reflexes were large, much higher than those evoked previously from the contralateral hemifield after the first lesion. This might be due to a process of disinhibition occurring in the superior colliculi.