500 Kilovolt Cathode Rays

The high potential x-ray tube at the California Institute has been modified so as to permit either x-rays or cathode rays to be produced. Electron currents up to 35 microamperes have been obtained through an aluminum window. A typical magnetic velocity spectrum of the high speed electrons passing out of an aluminum window is presented. The high velocity limit corresponds to about 500 kilovolts when the transformer voltage is 600 kilovolts peak. The velocity spectrum appears to be continuous and no absorption anomalies due to aluminum and lead foil are evident. The time required to obtain a velocity spectrum was reduced to a few minutes by allowing the electrons after being magnetically deflected, to pass through a copper foil into the air. The outside of the foil is coated with calcium tungstate and the photographic plate is placed in contact with the tungstate. It is noted that part of the photographic action of the high speed electrons is due to fluorescence of the glass backing of the photographic plates

Losing the Loss Calculation: Toward a More Just Sentencing Regime in White-Collar Criminal Cases

The sentencing regime that governs white-collar criminal cases requires reform. The U.S. Sentencing Guidelines recommend sentences that are generally too high and place a grossly disproportionate emphasis on the concept of loss -the dollar value of the harm that a court finds a white-collar criminal to have caused. This concept of loss is ill defined, and often artificial to the point of being arbitrary. Moreover, the loss calculation fails to adequately approximate a defendant\u27s culpability, dwarfing traditionally relevant considerations such as the manner in which the defendant committed the crime and the defendant\u27s motive for doing so. Fortunately, the Supreme Court has recently opened the door to systemic reform. In Kimbrough v. United States, the Supreme Court held that-at least in certain circumstances-a sentencing judge may deviate from a Guidelines recommendation based purely on policy disagreement with that guideline. This Note argues that sentencing judges should adopt an aggressive interpretation of the Supreme Court\u27s Kimbrough opinion and exercise their newly rediscovered discretion to deemphasize the loss calculation and restore rationality to the sentencing of white-collar criminals

Losing the Loss Calculation: Toward a More Just Sentencing Regime in White-Collar Criminal Cases

The sentencing regime that governs white-collar criminal cases requires reform. The U.S. Sentencing Guidelines recommend sentences that are generally too high and place a grossly disproportionate emphasis on the concept of loss -the dollar value of the harm that a court finds a white-collar criminal to have caused. This concept of loss is ill defined, and often artificial to the point of being arbitrary. Moreover, the loss calculation fails to adequately approximate a defendant\u27s culpability, dwarfing traditionally relevant considerations such as the manner in which the defendant committed the crime and the defendant\u27s motive for doing so. Fortunately, the Supreme Court has recently opened the door to systemic reform. In Kimbrough v. United States, the Supreme Court held that-at least in certain circumstances-a sentencing judge may deviate from a Guidelines recommendation based purely on policy disagreement with that guideline. This Note argues that sentencing judges should adopt an aggressive interpretation of the Supreme Court\u27s Kimbrough opinion and exercise their newly rediscovered discretion to deemphasize the loss calculation and restore rationality to the sentencing of white-collar criminals

500 Kilovolt Cathode Rays

The high potential x-ray tube at the California Institute has been modified so as to permit either x-rays or cathode rays to be produced. Electron currents up to 35 microamperes have been obtained through an aluminum window. A typical magnetic velocity spectrum of the high speed electrons passing out of an aluminum window is presented. The high velocity limit corresponds to about 500 kilovolts when the transformer voltage is 600 kilovolts peak. The velocity spectrum appears to be continuous and no absorption anomalies due to aluminum and lead foil are evident. The time required to obtain a velocity spectrum was reduced to a few minutes by allowing the electrons after being magnetically deflected, to pass through a copper foil into the air. The outside of the foil is coated with calcium tungstate and the photographic plate is placed in contact with the tungstate. It is noted that part of the photographic action of the high speed electrons is due to fluorescence of the glass backing of the photographic plates

Shaken Baby Syndrome as Felony Murder in North Carolina

This Article argues that the North Carolina criminal law’s treatment of Shaken Baby Syndrome should be reformed. Rather than leaving in place a legal regime that allows the state to prosecute all Shaken Baby Syndrome cases as first-degree murder, the law should distinguish between accidental and purposeful killings. If the state wishes to punish Shaken Baby Syndrome cases with special severity, the General Assembly should make this policy choice explicit. In making this argument, this Article proceeds in three parts. First, this Article examines how and why North Carolina subjects all Shaken Baby Syndrome deaths to prosecution as first-degree murder. Part I examines the two rules that, when combined, achieve this result: North Carolina’s felony murder rule, and the State’s codification of the crime of felonious child abuse. Second, this Article digs deeper into the felony murder doctrine, arguing that North Carolina’s felony murder rule is indefensible in the Shaken Baby Syndrome context. Finally, this Article’s conclusion suggests reform of the way the North Carolina criminal law treats Shaken Baby Syndrome cases. This Part argues for legislative and judicial reform that would limit North Carolina’s felony murder rule in child abuse cases. If the State wishes killing children to be punished more severely than killing an adult, the General Assembly should make that policy choice explicit. In the absence of such reforms, prosecutors should take it upon themselves to exercise sound discretion. Prosecutors should bring first-degree murder charges only in those Shaken Baby Syndrome cases that involve a defendant who acted with the premeditated design to kill or with knowledge that death would result from his actions

The focus of light - linear polarization breaks the rotational symmetry of the focal spot

We experimentally demonstrate for the first time that a linearly polarized beam is focussed to an asymmetric spot when using a high-numerical aperture focussing system. This asymmetry was predicted by Richards and Wolf [Proc.R.Soc.London A, 253, 358 (1959)] and can only be measured when a polarization insensitive sensor is placed in the focal region. We used a specially modified photodiode in a knife edge type set up to obtain highly resolved images of the total electric energy density distribution at the focus. The results are in good agreement with the predictions of a vectorial focussing theory.Comment: to be published in "Journal of Modern Optics

Changes in the Adhesive Properties of Spider Aggregate Glue During the Evolution of Cobwebs

We compare the prey capture glues produced by orb-weaving spiders (viscid glue) and their evolutionary descendents, the cobweb-weaving spiders (gumfoot glue). These glues are produced in homologous glands but exhibit contrasting structure, properties and response to changing humidity. Individual glue droplet stretching measurements indicate that the gumfoot glue behaves like a viscoelastic liquid in contrast to the viscid glue, which behaves like a viscoelastic solid. Moreover, the gumfoot glue is largely humidity-resistant – elasticity and adhesion are constant across variation in humidity and there is weak volume-dependence. Viscid glue, however, is highly humidity-sensitive. The glue expands an order of magnitude and demonstrates a monotonous reduction in elasticity under increased humidity, while glue adhesion optimizes at intermediate levels of humidity. We suggest that observed differences are due to different ‘tackifiers' used in these systems. These results shall inspire future efforts in fabricating stimuli-resistant and stimuli-sensitive materials

Monoclonal Antibodies to the V2 Domain of MN-rgp120: Fine Mapping of Epitopes and Inhibition of α4β7 Binding

BACKGROUND: Recombinant gp120 (MN-rgp120) was a major component of the AIDSVAX B/E vaccine used in the RV144 trial. This was the first clinical trial to show that vaccination could prevent HIV infection in humans. A recent RV144 correlates of protection study found that protection correlated with the presence of antibodies to the V2 domain. It has been proposed that antibodies to the α4β7 binding site in the V2 domain might prevent HIV-1 infection by blocking the ability of virions to recognize α4β7 on activated T-cells. In this study we investigated the specificity of monoclonal antibodies (MAbs) to the V2 domain of MN-rgp120 and examined the possibility that these antibodies could inhibit the binding of MN-rgp120 to the α4β7 integrin. METHODOLOGY/PRINCIPAL FINDINGS: Nine MAbs to the V2 domain were isolated from mice immunized with recombinant envelope proteins. The ability of these MAbs to inhibit HIV infection, block the binding of gp120 to CD4, and block the binding of MN-rgp120 to the α4β7 integrin was measured. Mutational analysis showed that eight of the MAbs recognized two immunodominant clusters of amino acids (166-168 and 178-183) located at either end of the C strand within the four-strand anti-parallel sheet structure comprising the V1/V2 domain. CONCLUSIONS/SIGNIFICANCE: These studies showed that the antigenic structure of the V2 domain is exceedingly complex and that MAbs isolated from mice immunized with MN-rgp120 exhibited a high level of strain specificity compared to MAbs to the V2 domain isolated from HIV-infected humans. We found that immunization with MN-rgp120 readily elicits antibodies to the V2 domain and some of these were able to block the binding of MN-rgp120 to the α4β7 integrin

The stochastic modelling of kleptoparasitism using a Markov process

Kleptoparasitism, the stealing of food items from other animals, is a common behaviour observed across a huge variety of species, and has been subjected to significant modelling effort. Most such modelling has been deterministic, effectively assuming an infinite population, although recently some important stochastic models have been developed. In particular the model of Yates and Broom (Stochastic models of kleptoparasitism. J. Theor. Biol. 248 (2007), 480–489) introduced a stochastic version following the original model of Ruxton and Moody (The ideal free distribution with kleptoparasitism. J. Theor. Biol. 186 (1997), 449–458), and whilst they generated results of interest, they did not solve the model explicitly. In this paper, building on methods used already by van der Meer and Smallegange (A stochastic version of the Beddington-DeAngelis functional response: Modelling interference for a finite number of predators. J. Animal Ecol. 78 (2009) 134–142) we give an exact solution to the distribution of the population over the states for the Yates and Broom model and investigate the effects of some key biological parameters, especially for small populations where stochastic models can be expected to differ most from their deterministic equivalents

Remote monitoring of vibrational information in spider webs

Spiders are fascinating model species to study information-acquisition strategies, with the web acting as an extension of the animal’s body. Here, we compare the strategies of two orb-weaving spiders that acquire information through vibrations transmitted and filtered in the web. Whereas Araneus diadematus monitors web vibration directly on the web, Zygiella x-notata uses a signal thread to remotely monitor web vibration from a retreat, which gives added protection. We assess the implications of these two information-acquisition strategies on the quality of vibration information transfer, using laser Doppler vibrometry to measure vibrations of real webs and finite element analysis in computer models of webs. We observed that the signal thread imposed no biologically relevant time penalty for vibration propagation. However, loss of energy (attenuation) was a cost associated with remote monitoring via a signal thread. The findings have implications for the biological use of vibrations by spiders, including the mechanisms to locate and discriminate between vibration sources. We show that orb-weaver spiders are fascinating examples of organisms that modify their physical environment to shape their information-acquisition strategy