Based on the Lotka–Volterra system, a pest-natural enemy model with nonlinear feedback control as well as nonlinear action threshold is introduced. The model characterizes the implementation of comprehensive prevention and control measures when the pest density reaches the nonlinear action threshold level depending on the pest density and its change rate. The mortality rate of the pest is a saturation function that strictly depends on their density while the release of natural enemies is also a nonlinear pulse (...) term depending on the density of real-time natural enemies. The exact impulsive and phase sets are given. The definition and properties of the Poincaré map corresponding to the pulse points on the phase set are provided. We investigate the existence and stability of boundary and interior order-1 periodic solution. The theoretical analysis developed in the present paper combined with nonlinear controlling measures as well as nonlinear action threshold methods and techniques laid the foundation for the establishment and analysis of other state-dependent feedback control models. (shrink)

Single-pulse and repetitive transcranial magnetic stimulation are used in clinical practice for diagnostic and therapeutic purposes. However, rTMS-based therapies that lead to a significant and sustained reduction in neuropsychiatric symptoms remain scarce. While it is generally accepted that the stimulation frequency plays a crucial role in producing the therapeutic effects of rTMS, less attention has been dedicated to determining the role of the electric field strength. Conventional threshold-based intensity selection approaches, such as the resting motor threshold, produce (...) variable stimulation intensities and electric fields across participants and cortical regions. Insufficient standardization of electric field strength may contribute to the variability of rTMS effects and thus therapeutic success. Computational approaches that can prospectively optimize the electric field and standardize it across patients and cortical targets may overcome some of these limitations. Here, we discuss these approaches and propose that electric field standardization will be instrumental for translational science frameworks aimed at deciphering the subcellular, cellular, and network mechanisms of rTMS. Advances in understanding these mechanisms will be important for optimizing rTMS-based therapies in psychiatry. (shrink)

ObjectiveThe effects and possible mechanisms of cerebellar high-frequency repetitive transcranial magnetic stimulation on swallowing-related neural networks were studied using resting-state functional magnetic resonance imaging.MethodA total of 23 healthy volunteers were recruited, and 19 healthy volunteers were finally included for the statistical analysis. Before stimulation, the cerebellar hemisphere dominant for swallowing was determined by the single-pulse TMS. The cerebellar representation of the suprahyoid muscles of this hemisphere was selected as the target for stimulation with 10 Hz rTMS, 100% resting motor (...) threshold, and 250 pulses, with every 1 s of stimulation followed by an interval of 9 s. The motor evoked potential amplitude of the suprahyoid muscles in the bilateral cerebral cortex was measured before and after stimulation to evaluate the cortical excitability. Forty-eight hours after elution, rTMS was reapplied on the dominant cerebellar representation of the suprahyoid muscles with the same stimulation parameters. Rs-fMRI was performed before and after stimulation to observe the changes in amplitude of low-frequency fluctuation and regional homology at 0.01–0.08 Hz, 0.01–0.027 Hz, and 0.027–0.073 Hz.ResultsAfter cerebellar high-frequency rTMS, MEP recorded from swallowing-related bilateral cerebral cortex was increased. The results of rs-fMRI showed that at 0.01–0.08 Hz, ALFF was increased at the pons, right cerebellum, and medulla and decreased at the left temporal lobe, and ReHo was decreased at the left insular lobe, right temporal lobe, and corpus callosum. At 0.01–0.027 Hz, ALFF was decreased at the left temporal lobe, and ReHo was decreased at the right temporal lobe, left putamen, and left supplementary motor area.ConclusionRepetitive transcranial magnetic stimulation of the swallowing cortex in the dominant cerebellar hemisphere increased the bilateral cerebral swallowing cortex excitability and enhanced pontine, bulbar, and cerebellar spontaneous neural activity, suggesting that unilateral high-frequency stimulation of the cerebellum can excite both brainstem and cortical swallowing centers. These findings all provide favorable support for the application of cerebellar rTMS in the clinical practice. (shrink)

Here we elucidate a paradox: how a single chemoattractant‐receptor system in two individuals is used for communication despite the seeming inevitability of self‐excitation. In the filamentous fungus Neurospora crassa, genetically identical cells that produce the same chemoattractant fuse via the homing of individual cell protrusions toward each other. This is achieved via a recently described “ping‐pong” pulsatile communication. Using a generic activator‐inhibitor model of excitable behavior, we demonstrate that the pulse exchange can be fully understood in terms of two (...) excitable systems locked into a stable oscillatory pattern of mutual excitation. The most puzzling properties of this communication are the sudden onset of oscillations with final amplitude, and the absence of seemingly inevitable self‐excitation. We show that these properties result directly from both the excitability threshold and refractory period characteristic of excitable systems. Our model suggests possible molecular mechanisms for the ping‐pong communication. (shrink)

An eight hundred‐square‐foot house greets me and a licensed practical nurse. We walk on uneven, disintegrating concrete steps before entering the patient's daughter's home, and we can see a haze of cigarette smoke before we enter the living room. Although the patient is old enough for retirement, she tells me that, if it were up to her, she would still be working. Noticing the medical equipment occupying her room—oxygen, pulse oximeter, and blood pressure machine—I am reminded that our health (...) system is trying, like many other systems across the country, to manage people's chronic illness better by bringing technology into patients’ homes in hopes of preventing hospital readmissions. For this patient, the hope is that, if she gets symptoms that suggest another exacerbation of her chronic obstructive pulmonary disease, she can manage it herself. If I hadn't spent hundreds of hours in patients’ homes, I would have a low threshold for ordering home‐based nursing and telehealth; it would often seem like a good solution. (shrink)

In the present study, we have demonstrated hysteresis phenomena in the excitability of single, enzymatically dissociated guinea pig ventricular myocytes. Membrane potentials were recorded with patch pipettes in the whole-cell current clamp configuration. Repetitive stimulation with depolarizing current pulses of constant cycle length and duration but varying strength led to predictable excitation (1:l) and non-excitation (1:0) patterns depending on current strength. In addition, transition between patterns depended on the direction of current intensity change and stable hysteresis loops were obtained in (...) stimulus:response pattern vs. current intensity plots in 14 cells. Increase of pulse duration and decrease of stimulation rate contributed to a reduction in hysteresis loop areas. Changes in amplitude and shape of the subthreshold responses during the transitions from one stable pattern to the other, suggested that activity led to an increase in membrane resistance, particularly in the voltage domain between resting potential, and threshold. Therefore, we modelled the dynamic behaviour of the single cells as a function of diastolic membrane resistance, using previously published analytical solutions. Numerical iteration of the analytical model equations closely reproduced the experimental hysteresis loops in both qualitative and quantitative ways. In particular, the effect of stimulation frequency on the model was similar to the experimental findings. The overall study suggests that the excitability pattern of guinea pig ventricular myocytes accounts for hysteresis and bistabilities when current intensity is allowed to fluctuate around threshold levels. (shrink)

Fourteen healthy children (13.8±2.2 years, range 10 to 16; M:F=5:9) received 30 Hz intermittent theta burst transcranial magnetic stimulation (iTBS) with a stimulation intensity of 70% of resting motor threshold (RMT) with a total of 300 (iTBS300) pulses. All volunteers were free of neurologic, psychiatric and serious medical illnesses, not taking any neuropsychiatric medications, and did not have any contraindications to Transcranial Magnetic Stimulation. Changes in the mean amplitudes of motor-evoked potentials from baseline following iTBS were expressed as a (...) ratio and assessed from 1 to 10 minutes (BLOCK1) and 1 to 30 minutes (BLOCK2) using repeated-measures analysis of variance. All 14 subjects completed iTBS300 over the dominant primary motor cortex (M1) without any clinically reported adverse events. ITBS300 produced significant M1 facilitation (F5,65=3.165, p=0.01) at BLOCK1 and trend level M1 facilitation at BLOCK2 (F10,129=1.69, p=0.089). Although iTBS300 (stimulation duration of 92 seconds at 70% RMT) delivered over M1 in typically developed children was well-tolerated and produced on average significant facilitatory changes in cortical excitability, the post-iTBS300 neurophysiologic response was variable in our small sample. ITBS300-induced changes may represent a potential neuroplastic biomarker in healthy children and those with neuro-genetic or neuro-psychiatric disorders. However, a larger sample size is needed to address safety and concerns of response variability. (shrink)

The issue of how basic sensory and temporal processing are related is still unresolved. We studied temporal processing, as assessed by simple visual reaction times (RT) and double-pulse resolution (DPR), in patients with partial vision loss after visual pathway lesions and investigated whether vision restoration training (VRT), a training program designed to improve light detection performance, would also affect temporal processing. Perimetric and campimetric visual field tests as well as maps of DPR thresholds and RT were acquired before and (...) after a 3 months training period with VRT. Patient performance was compared to that of age-matched healthy subjects. Intact visual field size increased during training. Averaged across the entire visual field, DPR remained constant while RT improved slightly. However, in transition zones between the blind and intact areas (areas of residual vision) where patients had shown between 20 and 80% of stimulus detection probability in pre-training visual field tests, both DPR and RT improved markedly. The magnitude of improvement depended on the defect depth (or degree of intactness) of the respective region at baseline. Inter-individual training outcome variability was very high, with some patients showing little change and others showing performance approaching that of healthy controls. Training-induced improvement of light detection in patients with visual field loss thus generalized to dynamic visual functions. The findings suggest that similar neural mechanisms may underlie the impairment and subsequent training-induced functional recovery of both light detection and temporal processing. (shrink)

Long time delay before lasing in a II-VI laser diode has been observed. Due to this delay, a nominal threshold current increases as the width of applied current pulse becomes shorter. This delay is attributed to the internal Q switching caused by the balance of injected carriers, temperature rise and gain-guiding. By fitting the calculated data to the experimental ones, rates of refractive index change with carrier concentration and with temperature have been estimated.

Unstable Accumulating Activator models for cellular size control propose an activator that accumulates in a size-dependent manner and triggers cell cycle progression once it has reached a certain threshold. Having a short half life makes such an activator responsive to changes in cell size and makes specific predictions for how cells respond to perturbation. In particular, it explains the curious phenomenon of excess mitotic delay. Excess mitotic delay, first observed in Tetrahymena in the '50s, is a phenomenon in which (...) a pulse of protein synthesis inhibition causes a delay in mitotic entry that is longer than the pulse and that gets longer the later in the cell cycle the pulse is delivered. The interpretation of this phenomenon championed by Zeuthen and Mitchison in the '60s and '70s is that an unstable activator of mitosis is degraded during the pulse and has to be resynthesized to a threshold level to trigger mitosis; small cells have more time to resynthesize the activator before mitosis and so suffer less excess delay, whereas, large cells have less time thus suffer greater excess delay. Fifty years later, with our detailed understanding of cell cycle biochemistry, we can identify and test candidate Unstable Accumulating Activators. Here I review the field and further develop this concept. Excess mitotic delay, the phenomenon in which inhibition of protein synthesis causes a longer delay than the pulse of inhibition, is consistent with cell size control by an unstable accumulating activator, but not a stable activator. (shrink)

Short-term limb immobilization results in skeletal muscle decline, but the underlying mechanisms are incompletely understood. This study aimed to determine the neurophysiologic basis of immobilization-induced skeletal muscle decline, and whether repetitive Transcranial Magnetic Stimulation could prevent any decline. Twenty-four healthy young males underwent unilateral limb immobilization for 72 h. Subjects were randomized between daily rTMS using six 20 Hz pulse trains of 1.5 s duration with a 60 s inter-train-interval delivered at 90% resting Motor Threshold, or Sham rTMS (...) throughout immobilization. Maximal grip strength, EMG activity, arm volume, and composition were determined at 0 and 72 h. Motor Evoked Potentials were determined daily throughout immobilization to index motor excitability. Immobilization induced a significant reduction in motor excitability across time. The rTMS intervention increased motor excitability at 0 h. Despite daily rTMS treatment, there was still a significant reduction in motor excitability, loss in EMG activity, and a loss of maximal grip strength after immobilization. Interestingly, the increase in biceps and posterior forearm skinfold thickness with immobilization in Sham treatment was not observed following rTMS treatment. Reduced MEPs drive the loss of strength with immobilization. Repetitive Transcranial Magnetic Stimulation cannot prevent this loss of strength but further investigation and optimization of neuroplasticity protocols may have therapeutic benefit. (shrink)

Despite the prominence of thresholds in theories of distributive justice, there is no general account of what sort of role is played by the idea of a threshold within such theories. This has allowed an ongoing lack of clarity and misunderstanding around views that employ thresholds. In this article, I develop an account of the concept of thresholds in distributive justice. I argue that this concept contains three elements, which threshold views deploy when ranking possible distributions. These elements (...) are (i) the level of the threshold, (ii) what constitutes the value of the threshold, and (iii) how benefits above and below the threshold must be allocated. I highlight three contributions that this particular account of thresholds makes: it clarifies the nature of the shift that occurs at the threshold; it resolves a common misunderstanding about headcount principles; and it shows how the arbitrariness objection can be met. (shrink)

Introduction: Critical realism, hegelian dialectic and the problems of philosophy preliminary considerations -- Objectives of the book -- Dialectic : an initial orientation -- Negation -- Four degrees of critical realism -- Prima facie objections to critical realism -- On the sources and general character of the hegelian dialectic -- On the immanent critique and limitations of the hegelian dialectic -- The fine structure of the hegelian dialectic -- Dialectic : the logic of absence, arguments, themes, perspectives, configurations -- Absence (...) -- Emergence -- Contradiction I : Hegel and Marx -- Contradiction II : misunderstandings -- On the materialist diffraction of dialectic -- Dialectical arguments and the unholy trinity -- Dialectical motifs : tina formation, mediation, concrete universality, etc -- On the generalized theory of the dialectical remark, the failure of detachment, and the presence of the past -- Dialectical critical naturalism -- Towards a real definition of dialectic -- Dialectical critical realism and the dialectic of freedom -- Ontology -- The dialectic of truth -- On the emergence and derivability of dialecticized transcendental realism -- 1m realism : non-identity -- 2e realism : negativity -- Space, time and tense -- Social science, explanatory critique, emancipatory axiology -- 3l realism : totality -- 4d realism : agency -- The dialectic of desire to freedom -- Dialectical critical realism and the dialectics of critical realism -- Metacritical dialectics : irrealism and its consequences -- Irrealism -- The problems of philosophy and their resolution -- Contradictions of the critical philosophy -- Dilemmas of the beautiful soul and the unhappy consciousness -- Master and slave : from dialectics of reconciliation to dialectics of liberation -- The metacritique of the hegelian dialectic -- Marxian dialectic i: the rational kernel in the mystical shell -- Marxian dialectic ii: the mystical shell in the rational kernel -- Metacritical dialectics : philosophical ideologies, their sublation and explanation -- The consequences of irrealism -- Diffracted and retotalized dialectics -- Dialectic as the pulse of freedom. (shrink)

The threshold problem is the task of adequately answering the question: “Where does the threshold lie between knowledge and lack thereof?” I start this paper by articulating two conditions for solving it. The first is that the threshold be neither too high nor too low; the second is that the threshold accommodate the significance of knowledge. In addition to explaining these conditions, I also argue that it is plausible that they can be met. Next, I argue (...) that many popular accounts of knowledge cannot meet them. In particular, I lay out a number of problems that standard accounts of knowledge face in trying to meet these conditions. Finally, near the end of this paper, I argue that there is one sort of account that seems to evade these problems. This sort of account, which is called a cluster account of knowledge, says that knowledge is to be accounted for in terms of truth, belief and a cluster of epistemic properties and also that knowledge doesn’t require having all members of the cluster, but merely some subset. (shrink)

Despite the prominence of thresholds and limits in theories of distributive justice, there is no general account of their role within such theories. This has allowed an ongoing lack of clarity and misunderstanding around threshold views in distributive justice. In this thesis, I develop an account of the conceptual structure of such views. Such an account helps understand and characterize threshold views, can subsume what may seem to be different debates about such views under one conceptual header, and (...) can be used to further examine and develop patterns of justice that draw on thresholds. In light of this account, I propose a novel characterization of sufficientarianism which sheds new light on the distinctiveness of sufficientarianism as a distributive principle and on the common objections to sufficientarianism. Moreover, I examine and defend limitarianism, which is the view that people should not have more than a certain amount of wealth. In particular, I argue in favour of limitarianism as a midlevel principle for guiding institutional design and individual actions and, furthermore, as a specification of what a just allocation of wealth requires under epistemic constraints. (shrink)

Le Souffle de la Terre/The Pulse of the Earth is an on-going sound work (1996–20–) by the artist L. Abenavoli. She outlines the sonification methods employed in the making of the work in an analysis of its technical and conceptual features. The work is described in terms of her artistic objectives.

Mental-threshold egalitarianism, well-known examples of which include Jeff McMahan’s two-tiered account of the wrongness of killing and Tom Regan’s theory of animal rights, divides morally considerable beings into equals and unequals on the basis of their individual mental capacities. In this paper, I argue that the line that separates equals from unequals is unavoidably arbitrary and implausibly associates an insignificant difference in empirical reality with a momentous difference in moral status. In response to these objections, McMahan has proposed the (...) introduction of an intermediate moral status. I argue that this move ultimately fails to address the problem. I conclude that, if we are not prepared to give up moral equality, our full and equal moral status must be grounded in a binary property that is not a threshold property. I tentatively suggest that the capacity for phenomenal consciousness is such a property, and a plausible candidate. (shrink)

The Threshold of the Visible World advances a revolutionary new political aesthetic--Kaja Silverman explores the possibilities for looking beyond the restrictive mandates of the self, and the normative aspects of the cultural image-repertoire. She provides a detailed account of the social and psychic forces which constrain us to look and identify in normative ways, and the violence which that normativity implies. Accounting for these phenomena on both a conscious and an unconcious level, Silverman analyzes the psychic and textual conditions (...) under which our "field of vision" can be expanded. The title of this book is taken from Lacan's essay on the mirror stage. In that text, Lacan writes that "the mirror-image would seem to be the threshold of the visible world." He thereby suggests that the visible world has no existence as such until the infant subject has access to an image of self. Lacan intimates that the mirror provides the frame through which one relates to others within the domain of vision, stressing the priority of narcissism and the ego over all other libidinal transactions. The Threshold of the Visible World provides a psychic, social and political specification of Lacan's claim, and most particularly of its implications for the subject's relations to the social other. This is accomplished through examination of the ego, as well as two other categories at the center of Lacan's account of the mirror stage: ideality and identification. This book is an ethical-political project which leads to the re-elaboration of a number of crucial theoretical categories--Silverman offers an account of the bodily ego, of identification, of idealization, of the gaze, of the look, and of the "photographic." The Threshold of the Visible World leads as well to the formulation of a fresh model for conceptualizing sexual, racial and class "difference," and the terms under which it might be dismantled. This book thus seeks to apprehend the field of vision through the frame of a different kind of bodily ego, and discover the pleasures to be derived from corporeal transport. (shrink)

How, and how well, do people switch between exploration and exploitation to search for and accumulate resources? We study the decision processes underlying such exploration/exploitation trade‐offs using a novel card selection task that captures the common situation of searching among multiple resources (e.g., jobs) that can be exploited without depleting. With experience, participants learn to switch appropriately between exploration and exploitation and approach optimal performance. We model participants' behavior on this task with random, threshold, and sampling strategies, and find (...) that a linear decreasing threshold rule best fits participants' results. Further evidence that participants use decreasing threshold‐based strategies comes from reaction time differences between exploration and exploitation; however, participants themselves report non‐decreasing thresholds. Decreasing threshold strategies that “front‐load” exploration and switch quickly to exploitation are particularly effective in resource accumulation tasks, in contrast to optimal stopping problems like the Secretary Problem requiring longer exploration. (shrink)

This paper provides an axiomatic analysis of sufficientarian social evaluation. Sufficientarianism has emerged as an increasingly important notion of distributive justice. We propose a class of principles that we label generalized critical-level sufficientarian orderings. The distinguishing feature of our new class is that its members exhibit constant critical levels of well-being that are allowed to differ from the threshold of sufficiency. Our basic axiom assigns priority to those below the threshold, a property that is shared by numerous other (...) sufficientarian approaches. When combined with the well-known strong Pareto principle and the assumption that there be a constant critical level, the axiom implies that the critical level cannot be below the threshold. The main results of the paper are characterizations of our new class and an important subclass. As a final observation, we identify the generalized critical-level sufficientarian orderings that permit us to avoid the repugnant conclusion and the sadistic conclusion, which are known as two fundamental challenges in population ethics. (shrink)

_Dialectic_ is now widely regarded as a classic of contemporary philosophy. This book, first published in 1993, sets itself three main aims: the development of a general theory of dialectic, of which Hegelian dialectic can be seen to be a special case; the dialectical enrichment and deepening of critical realism, viz. into the system of dialectical critical realism; and the outline of the elements of a totalizing critique of Western philosophy. The first chapter clarifies the rational core of Hegelian dialectic. (...) Chapter two then proceeds to develop a general theory of dialectic. Isolating the fallacy of 'ontological monovalence', Roy Bhaskar then shows how absence and other negating concepts such as contradiction have a legitimate and necessary ontological employment. He then goes on to give a synoptic account of key dialectical concepts such as the concrete universal; to sketch the further dialectical development of critical naturalism through an account of what he calls four-planar social being; and following consideration of the dialectical critique of analytical reason, he moves on to the real definition of dialectic as absenting absence and in the human sphere, the axiology of freedom. Chapter three extends and deepens critical realism’s characteristic concerns with ontology, science, social science and emancipation not only into the realms of negativity and totality, but also into the fields of reference and truth, spatio-temporality, tense and process, the logic of dialectical universalizability and on to the plane of ethics, where it articulates a combination of moral realism and ethical naturalism, whereby consideration of elemental desire involves commitment to the eudaimonistic society. This is then followed by a sublime discussion of key moments in the trajectory of Western philosophy, the tradition of which can now be seen to be based on what the author calls the unholy trinity of the epistemic fallacy or the reduction of being to knowledge, primal squeeze or the collapse of structure and alethic truth, and ontological monovalence. (shrink)

A small consortium of philosophers has begun work on the implications of epistemic networks (Zollman 2008 and forthcoming; Grim 2006, 2007; Weisberg and Muldoon forthcoming), building on theoretical work in economics, computer science, and engineering (Bala and Goyal 1998, Kleinberg 2001; Amaral et. al., 2004) and on some experimental work in social psychology (Mason, Jones, and Goldstone, 2008). This paper outlines core philosophical results and extends those results to the specific question of thresholds. Epistemic maximization of certain types does show (...) clear threshold effects. Intriguingly, however, those effects appear to be importantly independent from more familiar threshold effects in networks. (shrink)

Reflections on digital mourning in the wake of the mass shooting at the Pulse nightclub in Orlando 2016.

If you believe that there are restrictions on what we as moral agents can do to others, but that these restrictions can give way in the face of competing considerations, then you believe in thresholds for rights. In this dissertation I develop an account of thresholds for rights, in defence of a position which is often stated but rarely explained or defended. I begin with the obvious question: How much needs to be at stake before a right's claim is overridden? (...) ;Less obvious, but equally crucial, are questions about the distribution of the total which needs to be at stake. After developing a framework for answering that question, in subsequent chapters I deal with other factors which may influence our judgements about the overridability of rights' claims, including the numbers and identities of the agents involved. (shrink)

Clearly written for the beginning student, this text provides an introduction to Asian philosophy as found in India, China, and Japan. Its thematic approach covers the most significant questions in the areas of Oriental metaphysics, ontology, epistemology, and ethics as it successfully integrates historical and regional approaches. In addition to providing a solid basis for a sound grasp of the major teachings and leading figures and schools in Oriental thought, readings from Indian, Chinese, and Japanese sources help the student gain (...) some familiarity with primary sources. (shrink)

After spinal cord injury (SCI), motoneuron death occurs at and around the level of injury which induces changes in function and organization throughout the nervous system, including cortical changes. Muscle affected by SCI may consist of both innervated (accessible to voluntary drive) and denervated (inaccessible to voluntary drive) muscle fibers. Voluntary activation measured with transcranial magnetic stimulation (VATMS) can quantify voluntary cortical/subcortical drive to muscle but is limited by technical challenges including suboptimal stimulation of target muscle relative to its antagonist. (...) The motor evoked potential (MEP) in the biceps compared to the triceps (i.e., MEP ratio) may be a key parameter in the measurement of biceps VATMS after SCI. We used paired pulse TMS, which can inhibit or facilitate MEPs, to determine whether the MEP ratio affects VATMS in individuals with tetraplegia. Ten individuals with tetraplegia following cervical SCI and ten non-impaired individuals completed single pulse and paired pulse VATMS protocols. Paired pulse stimulation was delivered at 1.5, 10, and 30 ms inter-stimulus intervals (ISI). In both the SCI and non-impaired groups, the main effect of the stimulation pulse (paired pulse compared to single pulse) on VATMS was not significant in the linear mixed-effects models. In both groups for the stimulation parameters we tested, the MEP ratio was not modulated across all effort levels and did not affect VATMS. Linearity of the voluntary moment and superimposed twitch moment relation was lower in SCI participants compared to non-impaired. Poor linearity in the SCI group limits interpretation of VATMS. Future work is needed to address methodological issues that limit clinical application of VATMS. (shrink)

Application of egalitarian and prioritarian accounts of health resource allocation in low‐income countries have both been criticized for implying distribution outcomes that allow decreasing/undermining health gains and for tolerating unacceptable standards of health care and health status that result from such allocation schemes. Insufficient health care and severe deprivation of health resources are difficult to accept even when justified by aggregative efficiency or legitimized by fair deliberative process in pursuing equality and priority oriented outcomes. I affirm the sufficientarian argument that, (...) given extreme scarcity of public health resources in low‐income countries, neither health status equality between populations nor priority for the worse off is normatively adequate. Nevertheless, the threshold norm alone need not be the sole consideration when a country's total health budget is extremely scarce. Threshold considerations are necessary in developing a theory of fair distribution of health resources that is sensitive to the lexically prior norm of sufficiency. Based on the intuition that shares must not be taken away from those who barely achieve a minimal level of health, I argue that assessments based on standards of minimal physical/mental health must be developed to evaluate the sufficiency of the total resources of health systems in low‐income countries prior to pursuing equality, priority, and efficiency based resource allocation. I also begin to examine how threshold sensitive health resource assessment could be used in the Philippines. (shrink)

Robert Brain traces the origins of artistic modernism to specific technologies of perception developed in late-nineteenth-century laboratories. Brain argues that the thriving fin-de-siècle field of “physiological aesthetics,” which sought physiological explanations for the capacity to appreciate beauty and art, changed the way poets, artists, and musicians worked and brought a dramatic transformation to the idea of art itself.

A 10 kHz pulsed X-ray generator utilising a hot-cathode triode in conjunction with a new type of grid control device for controlling X-ray duration is described. The energy-storage condenser was charged up to 70 kV by a power supply, and the electric charges in the condenser were discharged to the X-ray tube repetitively by the grid control device. The maximum values of the grid voltage, the tube voltage, and the tube current were −1.5 kV, 70 kV, and 0.4 A, respectively. (...) The duration of the flash X-ray pulse was primarily determined by the time constant of the grid control device and the cut-off voltage of thermoelectrons. The X-ray duration was controlled within a region of less than 1 ms; the X-ray intensity with a pulse width of 0.27 ms, a charged voltage of 70 kV, and a peak tube current of 0.4 A was 0.92 μC kg −1 at 0.5 m per pulse. The maximum repetition rate was about 10 kHz, and the size of the focal spot was about 3.5×3.5 mm. (shrink)

Binarizing belief aggregation tackles the problem of aggregating individuals’ probabilistic beliefs on logically connected propositions into the group’s binary beliefs. One common approach to associating probabilistic beliefs with binary beliefs would be applying thresholds to probabilities. This paper aims to introduce and classify a range of threshold-based binarizing belief aggregation rules while characterizing them based on different forms of monotonicity and other properties.

Artist Meghan Moe Beitiks considers her first-person perspective of entanglements of light and air during the 2020–21 pandemic from her position in academia and Florida.

The continuity thesis of the Poznań school threshold model of the growth of scientific knowledge is considered in the light of the example of Van der Waals' and Boyle-Mariotte's laws. It is argued - using both traditional logical means and the structuralist reconstruction of the example - that the continuity thesis does not hold. A distinction between 'a historical and a systematic point of view' is introduced and it is argued that the continuity thesis of the threshold model (...) presupposes the systematic point of view. However, looking at matters from the systematic point of view need not yield the original theory, looked at from the historical point of view. Applied to the case of Van der Waals/Boyle-Mariotte laws, it turns out that the latter law is not a true idealizing special case of the former, contrary to the continuity thesis. The structuralist analysis of the example indicates that Boyle-Mariotte's law is a false factual law from the historical point of view. However, viewed from the systematic point of view, Boyle-Mariotte's law turns out to be a law which is expandable, adding the relevant new concepts, to an idealized version of Van der Waals' law. This idealizing version of Van der Waal's law in turn is a structuralist specialization of the (general) Van der Waals' law. (shrink)

The temporal widths of a light pulse as measured in different inertial frames are shown to have a relation more complicated than that of a simple time dilatation. The result is compared with the dilatation in the twin paradoxGedanken experiment. The light pulse measurement requires two observers in two different frames. The measurements of the observers are compared. For the twin experiment a comparison is made between two clocks which have undergone different histories between the two points at (...) which their world lines intersect. (shrink)

_Threshold Concepts in Problem-based Learning_ provides a critical discussion and guidance for educational researchers, teachers, innovators and policy makers wanting to explore the interrelationship of PBL and threshold concepts.

John McCumber; The Threshold of Bio-Ethics: Philosophical Warrant in the Thought of Stephen Erickson, Christian bioethics: Non-Ecumenical Studies in Medical Mor.

The threshold law for N-body fragmentation under dipole forces is formulated. It emerges from the energy dependence of the normalization of the correlated continuum wave function for N fragments. It is shown that the dipole threshold law plays a key role in understanding all threshold fragmentation phenomena since it links the classical threshold law for long-range Coulomb interactions to the statistical law for short-range interactions. Furthermore, a tunnelling mechanism is identified as the common feature which occurs (...) for all three classes of interactions, short-range, dipole and Coulomb. (shrink)

When should doctors seek protective custody to override a parent’s refusal of potentially lifesaving treatment for their child? The answer to this question seemingly has different answers for different subspecialties of pediatrics. This paper specifically looks at different thresholds for physicians overriding parental refusals of life-sustaining treatment between neonatology, cardiology, and oncology. The threshold for mandating treatment of premature babies seems to be a survival rate of 25–50%. This is not the case when the treatment in question is open (...) heart surgery for a child with congenital heart disease. Most cardiologists would not pursue legal action when parents refuse treatment, unless the anticipated survival rate after surgery is above 90%. In pediatric oncology, there are case reports of physicians requesting and obtaining protective custody for cancer treatment when the reported mortality rates are 40–50%. Such differences might be attributed to differences in care, a reasonable prioritization of quality of life over survival, or the role uncertainty plays on prognoses, especially for the extremely young. Nonetheless, other, non-medical factors may have a significant effect on inconsistencies in care across these pediatric subspecialties and require further examinations. (shrink)

According to an increasingly popular view in epistemology and philosophy of mind, beliefs are sensitive to contextual factors such as practical factors and salient error possibilities. A prominent version of this view, called credal sensitivism, holds that the context-sensitivity of belief is due to the context-sensitivity of degrees of belief or credence. Credal sensitivism comes in two variants: while credence-one sensitivism (COS) holds that maximal confidence (credence one) is necessary for belief, threshold credal sensitivism (TCS) holds that belief consists (...) in having credence above some threshold, where this threshold doesn’t require maximal confidence. In this paper, I argue that COS has difficulties in accounting for three important features about belief: i) the compatibility between believing p and assigning non-zero credence to certain error possibilities that one takes to entail not-p, ii) the fact that outright beliefs can occur in different strengths, and iii) beliefs held by unconscious subjects. I also argue that TCS can easily avoid these problems. Finally, I consider an alleged advantage of COS over TCS in terms of explaining beliefs about lotteries. I argue that lottery cases are rather more problematic for COS than TCS. In conclusion, TCS is the most plausible version of credal sensitivitism. (shrink)

This article has already been published, under Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License in Ephemera – Theory & Politics in Organization, 2019 volume 19 : p. 513-536. We thank William Davies for the permission to republish it here. abstract : In the context of ubiquitous data capture and the politics of control, there is growing individual and managerial interest in ‘pulse', both in the literal sense of arterial pulse - Rythmes des corps – Nouvel article.

This note is part of the implementation of a programme in foundations of mathematics to find exact threshold versions of all mathematical unprovability results known so far, a programme initiated by Weiermann. Here we find the exact versions of unprovability of the finite graph minor theorem with growth rate condition restricted to planar graphs, connected planar graphs and graphs embeddable into a given surface, assuming an unproved conjecture : ‘there is a number a>0 such that for all k≥3, and (...) all n≥1, the proportion of connected graphs among unlabelled planar graphs of size n omitting the k-element circle as minor is greater than a’. Let γ be the unlabelled planar growth constant . Let P be the following first-order arithmetical statement with real parameter c: “for every K there is N such that whenever G1,G2,…,GN are unlabelled planar graphs with Gishrink)

Categorical perception (CP) is said to occur when a continuum of equally spaced physical changes is perceived as unequally spaced as a function of category membership (Harnad, S. (Ed.) (1987). Psychophysical and cognitive aspects of categorical perception: A critical overview. Cambridge: Cambridge University Press). A common suggestion is that CP for color arises because perception is qualitatively distorted when we learn to categorize a dimension. Contrary to this view, we here report that English speakers show no evidence of lowered discrimination (...) thresholds at the boundaries between blue and green categories even though CP is found at these boundaries in a supra-threshold task. Furthermore, there is no evidence of different discrimination thresholds between individuals from two language groups (English and Korean) who use different color terminology in the blue-green region and have different supra-threshold boundaries. Our participants' just noticeable difference (JND) thresholds suggest that they retain a smooth continuum of perceptual space that is not warped by stretching at category boundaries or by within-category compression. At least for the domain of color, categorical perception appears to be a categorical, but not a perceptual phenomenon. (shrink)

A dynamic threshold, which controls the nature and course of learning, is a pivotal concept in Page's general localist framework. This commentary addresses various issues surrounding biologically plausible implementations for such thresholds. Relevant previous research is noted and the particular difficulties relating to the creation of so-called instance representations are highlighted. It is stressed that these issues also apply to distributed models.

The threshold view says that a person forms an outright belief P if and only if her credence for P reaches a certain threshold. Using computer simulations, I compare different versions of the threshold view to understand how they perform under time pressure in decision problems. The results illuminate the strengths and weaknesses of the various cognitive strategies in different decision contexts. A threshold view that performs well across diverse contexts is likely to be a cognitively (...) flexible and context-dependent fusion of several of the existing theories. The results of the simulations also cast doubts on the possibility of a threshold view that is both simple enough to streamline our reasoning while also allowing us to form good action-guiding beliefs. (shrink)