Search for Second and Third Generation Leptoquarks at CDF

We report the results of a search for second and third generation leptoquarks using 88 ${pb}^{-1}$ of data recorded by the Collider Detector at Fermilab. Color triplet technipions, which play the role of scalar leptoquarks, are investigated due to their potential production in decays of strongly coupled color octet technirhos. Events with a signature of two heavy flavor jets and missing energy may indicate the decay of a second (third) generation leptoquark to a charm (bottom) quark and a neutrino. As the data is found to be consistent with Standard Model expectations, mass limits are determined.Comment: Talk given at DPF2000, Columbus (OH), 9-12 Aug 2000. 3 pages, 4 figures. Submitted to Int.J.Mod.Phys.

Mental Training as a Tool in the Neuroscientific Study of Brain and Cognitive Plasticity

Although the adult brain was once seen as a rather static organ, it is now clear that the organization of brain circuitry is constantly changing as a function of experience or learning. Yet, research also shows that learning is often specific to the trained stimuli and task, and does not improve performance on novel tasks, even very similar ones. This perspective examines the idea that systematic mental training, as cultivated by meditation, can induce learning that is not stimulus or task specific, but process specific. Many meditation practices are explicitly designed to enhance specific, well-defined core cognitive processes. We will argue that this focus on enhancing core cognitive processes, as well as several general characteristics of meditation regimens, may specifically foster process-specific learning. To this end, we first define meditation and discuss key findings from recent neuroimaging studies of meditation. We then identify several characteristics of specific meditation training regimes that may determine process-specific learning. These characteristics include ongoing variability in stimulus input, the meta-cognitive nature of the processes trained, task difficulty, the focus on maintaining an optimal level of arousal, and the duration of training. Lastly, we discuss the methodological challenges that researchers face when attempting to control or characterize the multiple factors that may underlie meditation training effects

Turning on the alarm: the neural mechanisms of the transition from innocuous to painful sensation

The experience of pain occurs when the level of a stimulus is sufficient to elicit a marked affective response, putatively to warn the organism of potential danger and motivate appropriate behavioral responses. Understanding the biological mechanisms of the transition from innocuous to painful levels of sensation is essential to understanding pain perception as well as clinical conditions characterized by abnormal relationships between stimulation and pain response. Thus, the primary objective of this study was to characterize the neural response associated with this transition and the correspondence between that response and subjective reports of pain. Towards this goal, this study examined BOLD response profiles across a range of temperatures spanning the pain threshold. 14 healthy adults underwent functional magnetic resonance imaging (fMRI) while a range of thermal stimuli (44-49oC) were applied. BOLD responses showed a sigmoidal profile along the range of temperatures in a network of brain regions including insula and mid- cingulate, as well as a number of regions associated with motor responses including ventral lateral nuclei of the thalamus, globus pallidus and premotor cortex. A sigmoid function fit to the BOLD responses in these regions explained up to 85% of the variance in individual pain ratings, and yielded an estimate of the temperature of steepest transition from non-painful to painful heat that was nearly identical to that generated by subjective ratings. These results demonstrate a precise characterization of the relationship between objective levels of stimulation, resulting neural activation, and subjective experience of pain and provide direct evidence for a neural mechanism supporting the nonlinear transition from innocuous to painful levels along the sensory continuum

Persistent Homology in Sparse Regression and its Application to Brain Morphometry

Sparse systems are usually parameterized by a tuning parameter that determines the sparsity of the system. How to choose the right tuning parameter is a fundamental and difficult problem in learning the sparse system. In this paper, by treating the the tuning parameter as an additional dimension, persistent homological structures over the parameter space is introduced and explored. The structures are then further exploited in speeding up the computation using the proposed soft-thresholding technique. The topological structures are further used as multivariate features in the tensor-based morphometry (TBM) in characterizing white matter alterations in children who have experienced severe early life stress and maltreatment. These analyses reveal that stress-exposed children exhibit more diffuse anatomical organization across the whole white matter region.Comment: submitted to IEEE Transactions on Medical Imagin

Phenotypic Mapping of The Chicken Embryonic Thymic Microenvironment Developing Within an Organ Culture System

The chicken thymic microenvironment, as it developed in an embryonic thymus organ culture system, was phenotypically mapped using a panel of mAb defining both epithelial and nonepithelial stromal cell antigens. We have previously reported that thymocyte proliferation and differentiation will proceed for up to 6–8 days in thymus organ culture, hence demonstrating the functional integrity of the thymic microenvironment in vitro. During this time, the stromal component reflected that of the normal embryo with cortical and medullary epithelial areas readily identifiable by both morphology and surface-antigen expression. An abundance of subcapsular and cortical epithelial antigens was detected in the cultured thymus, particularly those normally expressed by the epithelium lining the capsule, trabeculae, and vascular regions (type epithelium) in the adult and embryonic thymus. Medullary epithelial antigens developed in organ culture, although were present in lower frequency than observed in the age-matched embryonic thymus. MHC class II expression by both epithelial and nonepithelial cells was maintained at high levels throughout the culture period. With increasing time in culture, the ratio of epithelial to nonepithelial cells decreased, concurrent with a decrease in thymocyte frequency and suggestive of a bidirectional interaction between these two cell types. Thus, a functionally intact thymic microenvironment appears to be maintained in embryonic thymus organ culture, a model that is currently being exploited to assess the role of stromal antigens, as defined by our mAb, in the process of thymopoiesis

Failure to regulate: counterproductive recruitment of top-down prefrontal-subcortical circuitry in major depression

Although depressed mood is a normal occurrence in response to adversity in all individuals, what distinguishes those who are vulnerable to major depressive disorder (MDD) is their inability to effectively regulate negative mood when it arises. Investigating the neural underpinnings of adaptive emotion regulation and the extent to which such processes are compromised in MDD may be helpful in understanding the pathophysiology of depression. We report results from a functional magnetic resonance imaging study demonstrating left-lateralized activation in the prefrontal cortex (PFC) when downregulating negative affect in nondepressed individuals, whereas depressed individuals showed bilateral PFC activation. Furthermore, during an effortful affective reappraisal task, nondepressed individuals showed an inverse relationship between activation in left ventrolateral PFC and the amygdala that is mediated by the ventromedial PFC (VMPFC). No such relationship was found for depressed individuals, who instead show a positive association between VMPFC and amygdala. Pupil dilation data suggest that those depressed patients who expend more effort to reappraise negative stimuli are characterized by accentuated activation in the amygdala, insula, and thalamus, whereas nondepressed individuals exhibit the opposite pattern. These findings indicate that a key feature underlying the pathophysiology of major depression is the counterproductive engagement of right prefrontal cortex and the lack of engagement of left lateral-ventromedial prefrontal circuitry important for the downregulation of amygdala responses to negative stimuli

The National Program for Solar Energy

On October 26, 1974, the Solar Energy Research Development and Demonstration Act was signed into law authorizing a vigorous federal program of research development and demonstration to establish solar energy as a viable energy resource. Solar heating and cooling of buildings represents a midterm help in an attempt to be less dependent on oil and natural gas. Many other solar programs are underway in the development of solar energy

The Skeleton of a Data Breach: The Ethical and Legal Concerns

After over thirty data breaches spanning the third and fourth quarter of 2012, Forbes magazine labeled the summer of 2012 as “The Summer of the Data Breach.” Four years later, businesses across multiple industries have suffered brand-image damage and paid millions of dollars in remedial expenses; we are living in the era of the mega breach. In 2014, companies such as Target, Home Depot, JP Morgan Chase, Anthem, Sony, UPS, Jimmy John’s, Kmart, Neiman Marcus, Community Health Systems, and the White House suffered data breaches. The Home Depot breach alone resulted in the loss of “56 million credit card accounts,” “53 million email addresses,” and an estimated 63 million dollars in damage. In addition to the economic fallout associated with data breaches, the 2015 Ashley Madison data breach highlighted the personal toll faced by consumers when their “private” information becomes “public.” That data breach exposed the identities of millions of would-be philanderers, shaming not only the subscribers to Ashley Madison’s service, but also innocent bystanders such as their family members. The frequency of data breaches has shown no signs of abating in 2016—in the first quarter, multiple hospitals fell victim to “ransomware,” a data breach that allows hackers to literally hold patient data hostage.7 Several hospitals had to pay hackers to regain access to their patients’ data. “Decentralized technology” creates a different set of problems than the simple misuse of a single individual’s “technological profile” and information. Today, unauthorized access to electronic information, a result of what Burnham in 1983 referred to as “transactional information,” includes “hackers breaking into systems or networks, third parties accessing personal information on lost laptops or other mobile devices, or organizations failing to dispose of personal information securely.” Data breaches exemplify the first type of unauthorized access and despite their frequent occurrence, they are little examined from an ethical standpoint. Though Google Scholar lists over 82,000 entries under “ethics of a data breach,” very few combine both terms in the title. One article that does so notes a “dearth of prior organizational-level privacy research, which has largely overlooked ethical issues or the personal harms often caused by privacy violations.” Even within the field of technology, “there has not been a huge literature on ethics within the mainstream of information systems journals.” Part of the problem is the novelty of data breach cases. They are so new and different that they appear to be technologically, morally, and legally unlike other problems. We suggest that analogies and analyses exist which can help resolve some of these moral and legal puzzles