Origin and reduction of wakefields in photonic crystal accelerator cavities

Photonic crystal (PhC) defect cavities that support an accelerating mode tend to trap unwanted higher-order modes (HOMs) corresponding to zero-group-velocity PhC lattice modes at the top of the bandgap. The effect is explained quite generally from photonic band and perturbation theoretical arguments. Transverse wakefields resulting from this effect are observed in a hybrid dielectric PhC accelerating cavity based on a triangular lattice of sapphire rods. These wakefields are, on average, an order of magnitude higher than those in the waveguide-damped Compact Linear Collider (CLIC) copper cavities. The avoidance of translational symmetry (and, thus, the bandgap concept) can dramatically improve HOM damping in PhC-based structures.Comment: 11 pages, 18 figures, 2 table

Impact of different handling styles (good vs. adverse) on growth performance, behavior, and cortisol concentrations in beef cattle

Our objective was to determine effects of aggressive handling on growth performance, behavior, and cortisol concentrations in beef calves. Crossbred calves (313 ± 4.7 kg; n = 54; 24 steers, 30 heifers) from a single herd were stratified by gender, body weight, and initial chute score, then allocated randomly to one of six pens. Each pen was randomly assigned to one of two handling treatments (good or adverse) applied on days 7, 35, 63, and 91. The objective of good treatment was to handle the calves quietly and gently to minimize stress. The objective of adverse treatment was to move the calves quickly and expose them to stimuli. Body weight, exit velocity, and chute scores (based on 5 point subjective scale) were recorded and salivary samples for cortisol were collected (4 calves/ pen) on days 0, 7, 35, 63, and 91. Pen scores (5 point subjective scale) were recorded on days 12, 42, and 87. Data were analyzed statistically using a mixed model. Chute scores tended to be higher (more agitated) in the adverse treatment on day 7, but scores did not differ on subsequent days (treatment × day; P = 0.06). Salivary cortisol concentrations on day 63 were greater in cattle on the adverse treatment (treatment × day, P = 0.001). Body weight, exit velocity, and pen scores were not affected by treatment (P ≥ 0.24). While differences were observed, these cattle appeared to acclimate to short-term adverse handling which did not seem to dramatically affect performance or behavior of beef cattle

Ecologic and geographic distribution of filovirus disease

Centers for Disease Control and Prevention http://www.cdc.gov/ncidod/EID/vol10no1/03-0125.htmWe used ecologic niche modeling of outbreaks and sporadic cases of filovirus-associated hemorrhagic fever (HF) to provide a large-scale perspective on the geographic and ecologic distributions of Ebola and Marburg viruses. We predicted that filovirus would occur across the Afrotropics: Ebola HF in the humid rain forests of central and western Africa, and Marburg HF in the drier and more open areas of central and eastern Africa. Most of the predicted geographic extent of Ebola HF appear to have been observed; Marburg HF has the potential to occur farther south and east. Ecologic conditions appropriate for Ebola HF are also present in Southeast Asia and the Philippines, where Ebola Reston is hypothesized to be distributed. This first large-scale ecologic analysis provides a framework for a more informed search for taxa that could constitute the natural reservoir for this virus family

Bench-to-bedside review: Developmental influences on the mechanisms, treatment and outcomes of cardiovascular dysfunction in neonatal versus adult sepsis

Sepsis is a significant cause of morbidity and mortality in neonates and adults, and the mortality rate doubles in patients who develop cardiovascular dysfunction and septic shock. Sepsis is especially devastating in the neonatal population, as it is one of the leading causes of death for hospitalized infants. In the neonate, there are multiple developmental alterations in both the response to pathogens and the response to treatment that distinguish this age group from adults. Differences in innate immunity and cytokine response may predispose neonates to the harmful effects of pro-inflammatory cytokines and oxidative stress, leading to severe organ dysfunction and sequelae during infection and inflammation. Underlying differences in cardiovascular anatomy, function and response to treatment may further alter the neonate's response to pathogen exposure. Unlike adults, little is known about the cardiovascular response to sepsis in the neonate. In addition, recent research has demonstrated that the mechanisms, inflammatory response, response to treatment and outcome of neonatal sepsis vary not only from that of adults, but vary among neonates based on gestational age. The goal of the present article is to review key pathophysiologic aspects of sepsis-related cardiovascular dysfunction, with an emphasis on defining known differences between adult and neonatal populations. Investigations of these relationships may ultimately lead to 'neonate-specific' therapeutic strategies for this devastating and costly medical problem