Effects of CSF hormones and ionic composition on salt/water metabolism

This collaborative agreement between Drs. Severs and Keil began in 1981, arising from a continuing interest in the issue of what, exactly, are the consequences of headward fluid shifts during manned spaceflight. Such shifts were recognized early by both U.S. and Soviet Scientists because of signs and symptoms referable to the head. Some of these include disturbed vision, puffiness in the face and periorbital areas, headache, vestibular dysfunction and distended jugular veins. We posited that the fluid shift had an immediate effect on the brain, and a long-term action requiring a neural interpretation of the flight environment. This would re-adjust both efferent neural as well as hormonal mechanisms to sustain cardiovascular and fluid/electrolyte balance consonent with survival in microgravity. Work along these lines is summarized

Effects of the anti-sucking device «SuckStop Müller» on calf behavior.

INTRODUCTION When cross-sucking persists beyond calf-hood, it represents an important problem in dairy heifers and cows. It can cause teat injuries and severe mastitis and lead to significant economic losses. The «SuckStop Müller,» a novel anti-sucking device, is designed to give the calf a negative feedback when cross-sucking on a conspecific. The aim of this study was to assess whether wearing a SuckStop would result in behavioral changes other than cross-sucking and thus, impair welfare in the short- and longer-term. Sixteen group-housed calves were observed in groups of four on five days, before and after fitting the SuckStop: day -2, day -1, day 0, day 1, and day 9. Maintenance behaviors (e.g., feeding, drinking, lying) were recorded using instantaneous scan sampling. In addition, the frequency of contact behaviors (e.g., exploring the feeding fence, touching own body) was recorded by means of continuous focal animal observations. Contact behaviors were classified as «impaired» or «normal» depending on whether or not the calf flinched in response to the contact. Finally, the number of visits to the milk and concentrate feeders was extracted from the computer-controlled feeding system. Fitting a SuckStop resulted in a higher proportion of observations spent lying and less exploration behavior on day 0 and day 1 than on day -2, day -1, and day 9. On day 0 and day 1, 6,3 % of exploration behaviors were classified as impaired, compared to 0,4 % (day -2, day -1) before and 0,2 % (day 9) after fitting the SuckStop. On day 9, all calves had superficial ulcerations on the nasal septum. In four calves, these ulcerations were moderately severe, whereas all other calves had slight ulcerations. In summary, the calves habituated quickly to this novel anti-sucking device. Follow-up studies are necessary to assess the long-term relevance of tissue alterations in the nasal septum for calf welfare as well as the effect of the SuckStop on cross-sucking behavior

Image segmentation by graph partitioning

In this paper we propose an hybrid method for the image segmentation which combines the edge-based, region-based and the morphological techniques in conjunction through the spectral based clustering approach. An initial partitioning of the image into atomic regions is set by applying a watershed method to the image gradient magnitude. This initial partition is the input to a computationally efficient region segmentation process which produces the final segmentation. We have applied our approach on several images of the Berkeley Segmentation Dataset. The results reveal the accuracy of the propose method

Simplicity and complexity preferences in causal explanation: An opponent heuristic account

People often prefer simple to complex explanations because they generally have higher prior probability. However, simpler explanations are not always normatively superior because they often do not account for the data as well as complex explanations. How do people negotiate this trade-off between prior probability (favoring simple explanations) and goodness-of-fit (favoring complex explanations)? Here, we argue that people use opponent heuristics to simplify this problem—that people use simplicity as a cue to prior probability but complexity as a cue to goodness-of-fit. Study 1 finds direct evidence for this claim. In subsequent studies, we examine factors that lead one or the other heuristic to predominate in a given context. Studies 2 and 3 find that people have a stronger simplicity preference in deterministic rather than stochastic contexts, while Studies 4 and 5 find that people have a stronger simplicity preference for physical rather than social causal systems, suggesting that people use abstract expectations about causal texture to modulate their explanatory inferences. Together, we argue that these cues and contextual moderators act as powerful constraints that can help to specify the otherwise ill-defined problem of what distributions to use in Bayesian hypothesis comparison.</p

Polymer-based controlled-release fed-batch microtiter plate - diminishing the gap between early process development and production conditions

Background: Fed-batch conditions are advantageous for industrial cultivations as they avoid unfavorable phenomena appearing in batch cultivations. Those are for example the formation of overflow metabolites, catabolite repression, oxygen limitation or inhibition due to elevated osmotic concentrations. For both, the early bioprocess development and the optimization of existing bioprocesses, small-scale reaction vessels are applied to ensure high throughput, low costs and prompt results. However, most conventional small-scale procedures work in batch operation mode, which stands in contrast to fed-batch conditions in large-scale bioprocesses. Extensive expenditure for installations and operation accompany almost all cultivation systems in the market allowing fed-batch conditions in small-scale. An alternative, more cost efficient enzymatic glucose release system is strongly influenced by environmental conditions. To overcome these issues, this study investigates a polymer-based fed-batch system for controlled substrate release in microtiter plates. Results: Immobilizing a solid silicone matrix with embedded glucose crystals at the bottom of each well of a microtiter plate is a suitable technique for implementing fed-batch conditions in microtiter plates. The results showed that the glucose release rate depends on the osmotic concentration, the pH and the temperature of the medium. Moreover, the applied nitrogen source proved to influence the glucose release rate. A new developed mathematical tool predicts the glucose release for various media conditions. The two model organisms E. coli and H. polymorpha were cultivated in the fed-batch microtiter plate to investigate the general applicability for microbial systems. Online monitoring of the oxygen transfer rate and offline analysis of substrate, product, biomass and pH confirmed that fed-batch conditions are comparable to large-scale cultivations. Furthermore, due to fed-batch conditions in microtiter plates, product formation could be enhanced by the factor 245 compared to batch cultivations. Conclusions: The polymer-based fed-batch microtiter plate represents a sophisticated and cost efficient system to mimic typical industrial fed-batch conditions in small-scale. Thus, a more reliable strain screening and early process development can be performed. A systematical scale-down with low expenditure of work, time and money is possible. © 2019 The Author(s)

Simplicity and complexity preferences in causal explanation: An opponent heuristic account

People often prefer simple to complex explanations because they generally have higher prior probability. However, simpler explanations are not always normatively superior because they often do not account for the data as well as complex explanations. How do people negotiate this trade-off between prior probability (favoring simple explanations) and goodness-of-fit (favoring complex explanations)? Here, we argue that people use opponent heuristics to simplify this problem—that people use simplicity as a cue to prior probability but complexity as a cue to goodness-of-fit. Study 1 finds direct evidence for this claim. In subsequent studies, we examine factors that lead one or the other heuristic to predominate in a given context. Studies 2 and 3 find that people have a stronger simplicity preference in deterministic rather than stochastic contexts, while Studies 4 and 5 find that people have a stronger simplicity preference for physical rather than social causal systems, suggesting that people use abstract expectations about causal texture to modulate their explanatory inferences. Together, we argue that these cues and contextual moderators act as powerful constraints that can help to specify the otherwise ill-defined problem of what distributions to use in Bayesian hypothesis comparison.</p

The Determinants of Knowability

Many propositions are not known to be true or false, andmany phenomena are not understood. What determineswhat propositions and phenomena are perceived asknowable or unknowable? We tested whether factorsrelated to scientific methodology (a proposition’sreducibility and falsifiability), its intrinsic metaphysics (themateriality of the phenomena and its scope ofapplicability), and its relation to other knowledge (itscentrality to one’s other beliefs and values) influenceknowability. Across a wide range of naturalistic scientificand pseudoscientific phenomena (Studies 1 and 2), as wellas artificial stimuli (Study 3), we found that reducibilityand falsifiability have strong direct effects on knowability,that materiality and scope have strong indirect effects (viareducibility and falsifiability), and that belief and valuecentrality have inconsistent and weak effects onknowability. We conclude that people evaluate theknowability of propositions consistently with principlesproposed by epistemologists and practicing scientists

Preferences for explanation generality develop early in biology but not physics

One of the core functions of explanation is to support prediction and generalization. However, some explanations license a broader range of predictions than others. For instance, an explanation about biology could be presented as applying to a specific case (e.g., “this bear”) or more generally across “all animals.” The current study investigated how 5- to 7-year-olds (N=36), 11- to 13-year-olds (N=34), and adults (N=79) evaluate explanations at varying levels of generality in biology and physics. Findings revealed that even the youngest children preferred general explanations in biology. However, only older children and adults preferred explanation generality in physics. Findings are discussed in light of differences in our intuitions about biological and physical principles

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man

Trapping cold atoms using surface-grown carbon nanotubes

We present a feasibility study for loading cold atomic clouds into magnetic traps created by single-wall carbon nanotubes grown directly onto dielectric surfaces. We show that atoms may be captured for experimentally sustainable nanotube currents, generating trapped clouds whose densities and lifetimes are sufficient to enable detection by simple imaging methods. This opens the way for a novel type of conductor to be used in atomchips, enabling atom trapping at sub-micron distances, with implications for both fundamental studies and for technological applications