Three-dimensional optical transfer of rotating beams.

Systems in which the point spread function (PSF) is a rotating beam have increasing use in three-dimensional (3D) microscopy and depth estimation. We analyze in several ways the 3D optical transfer function (OTF) of Gauss Laguerre modes and rotating beams. This is based on analysis of 3D OTFs of general aperture functions. Consequently, we suggest a criterion for depth resolution based on an effective cutoff of the axial frequency response. This criterion can be used to optimize PSFs explicitly and directly, to maximize axial resolution.

Framing physical activity as a distinct and uniquely valuable behavior independent of weight management: a pilot randomized controlled trial for overweight and obese sedentary persons.

PURPOSE: Promoting benefits of physical activity independent of weight management may help overweight/obese persons. DESIGN: Pilot randomized-controlled-trial. SUBJECTS: Twenty-six sedentary, overweight/obese persons receiving health-care at Stanford Medical Center, no contraindications for exercise. CONTROL/INTERVENTION GROUPS: Usual medical care and community weight-management/fitness resources versus same plus a brief intervention derived from behavioral-economic and evolutionary psychological theory highlighting benefits of activity independent of weight-management. ANALYSIS: Intent-to-treat. Cohen's d effect-sizes and 95% confidence intervals (95%CI) for changes in moderate-intensity-equivalent physical activity/week, cardiorespiratory fitness, and depression at 3 months relative to baseline. RESULTS: Intervention group participants demonstrated 3.76 hour/week of increased physical activity at study endpoint, controls only 0.7 hours/week (Cohen's d=0.74, 95% CI -0.06 to +1.5). They also improved cardiorespiratory fitness (Cohen's d=0.51, 95% CI -0.3 to +1.3) and reduced depression relative to controls (Cohen's d=0.66, 95% CI -0.1 to +1.4). CONCLUSION: Promoting activity independent of weight-management appears promising for further study.

Effects of a Standard American Diet and an anti-inflammatory diet in male and female mice.

BACKGROUND: Obesity and chronic pain are prevalent concerns. Pain is frequently experienced in weight-bearing joints, but is common in other areas of the body as well, suggesting other factors. Poor diet often contributes to obesity and can directly influence the immune system. We have shown that poor diet prolongs recovery from inflammatory injury. Therefore, our goal was to determine whether poor-quality diet-induced consequences could be prevented or reversed by an anti-inflammatory diet (AID). METHODS: A Standard American Diet (SAD) was developed to investigate the effects of poor diet on pain. The SAD includes amounts of refined sugar, carbohydrates and fats that better model the typical American diet, as compared to high-fat diets. We developed an AID to explore whether the effects of the SAD could reverse or whether the AID would enhance recovery prophylactically. The AID was developed using ingredients (epigallocatechin gallate, sulforaphane, resveratrol, curcumin and ginseng) with known anti-inflammatory properties. Following 15 weeks of diet [SAD, AID or regular (REG)] exposure, male and female mice underwent inflammatory injury, at which point some animals had their diets switched for the remainder of the study. RESULTS: Animals who consumed the SAD showed longer recovery compared to the AID- and REG-fed animals. Animals switched off the SAD had faster recovery times, with AID-fed animals recovering as fast as REG-fed animals. CONCLUSIONS: Poor diet prolonged recovery from inflammatory injury. Substitution of SAD with AID or REG promoted faster recovery. These findings suggest diet can be used as a non-pharmacological intervention following injury. SIGNIFICANCE: Obesity may increase susceptibility to chronic pain often due to poor diet. Diet has potential to be used as treatment for pain. This study investigates the use of a novel translatable diet to act as a preventative (i.e. prior to surgery) or an intervention (i.e. following an injury).

Human growth hormone and insulin-like growth factor-1 enhance the proliferation of human leukemic blasts.

As the number of long-term survivors of childhood leukemia increases, growth retardation has emerged as a significant complication. Treatment of these children with growth hormone (GH) has been suggested and sporadically implemented. We, therefore, studied the effect of human GH (hGH) and its by-product insulin-like growth factor-1 (IGF-1) on the growth of leukemic cells in vitro. Under serum-free conditions hGH and IGF-1 induced a significant dose-dependent proliferative effect on promyelocytic leukemia (HL60) and Burkitt's lymphoma (Daudi) cell lines. Anti-hGH antibodies negated the stimulatory effect of hGH and anti-IGF-1 serum abrogated the growth-promoting effect enhanced by IGF-1. Similar statistically significant stimulatory properties were found when freshly obtained marrow cells from four of five acute lymphoblastic leukemia (ALL) of childhood and four acute myelogenous leukemia (AML) patients were studied in ALL and AML blast-cell clonogenic assays. ALL colonies increased numerically by 72% (P less than .025) and AML colonies by 92% (P less than .01) in the presence of hGH at concentrations of 2.5 x 10(2) and 3.0 x 10(2) ng/mL, respectively. IGF-1 stimulated ALL and AML blast-colony growth at concentrations ranging from 0.05 to 0.5 ng/mL by up to 105% (P less than .025) and 65% (P less than .03), respectively. Our in vitro data suggest that circulating hGH and IGF-1 may promote leukemic blast cell replication in vivo, and the supplemental administration of hGH to leukemia patients in remission must be carefully monitored for early relapse.

Ribosomal frameshifting at the Gag-Pol junction in avian leukemia sarcoma virus forms a novel cleavage site.

The Gag and Gag-Pol precursors of avian sarcoma leukemia virus (ASLV) are translated from viral genomic-size mRNA at a molar ratio of about 20:1. Translation of Gag is terminated at the stop codon UAG located at the carboxyl-terminus of the viral protease (PR), whereas a ribosomal frameshift occurring at the carboxyl-terminus of Gag allows translation of the Gag-Pol precursor. To determine how PR is released from the Gag-Pol precursor, a single base (A or T) was inserted at the Gag-Pol junction in order to adjust the translation into a single reading frame. These mutations allow processing of the viral precursor when expressed in bacterial cells, but cause cessation of viral production after transfection of avian cells. The viral PR released from the large precursor is one amino acid longer than PR cleaved from the Gag polyprotein and is terminated by an Ile instead of a Leu residue.

Almost linear VC-dimension bounds for piecewise polynomial networks

We compute upper and lower bounds on the VC dimension and pseudo-dimension of feedforward neural networks composed of piecewise polynomial activation functions. We show that if the number of layers is fixed, then the VC dimension and pseudo-dimension grow as WlogW, where W is the number of parameters in the network. This result stands in opposition to the case where the number of layers is unbounded, in which case the VC dimension and pseudo-dimension grow as W2. We combine our results with recently established approximation error rates and determine error bounds for the problem of regression estimation by piecewise polynomial networks with unbounded weights.

Best estimated inverse versus inverse of the best estimator.

The construction of a feed-forward controller frequently requires the estimation of an inverse function. Two possible methods to achieve this are: (i) learning the best estimated inverse (BEI), a method that is sometimes referred to as direct inverse learning and (ii) learning the inverse of the best estimator (IBE), a method that is sometimes referred to as indirect inverse learning. We analyze a general control problem, in the presence of noise, and show analytically that these two methods are asymptotically significantly different, even for simple linear non-redundant systems. We further demonstrate that the IBE method is typically superior for control purposes.

Molecular typing of infectious bursal disease virus of Israeli field and vaccine strains by the reverse transcription/polymerase chain reaction/restriction fragment length polymorphism assay.

Infectious bursal disease viruses (IBDVs) were examined by testing bursa samples from 37 commercially reared chicken flocks and three vaccine strains by the reverse transcription (RT)/polymerase chain reaction (PCR)/restriction fragment length polymorphism assay (RFLP). The assay was conducted with a 717-bp fragment of the VP2 gene with the restriction enzymes BstNI and MboI. The presence of a restriction site for SspI was used to predict a very virulent phenotype. Results indicated the existence of two molecular groups within the field isolates; four samples showed one pattern of RFLPs, and the majority, 30 out of the 37 tested, showed a second RFLP pattern. Three samples tested negative for IBDV. Eight bursa samples, representing the two molecular groups, were also tested by the RT/PCR/RFLP assay as developed by Jackwood. A comparison of the RFLP profiles by the two methods indicated that four isolates belonged to molecular group 6 and 30 isolates belonged to a new molecular group. All field isolates had a very virulent phenotype. One vaccine strain, produced from a local isolate, was classified as molecular group 6. The other two vaccine strains had RFLPs that differed from those of the field isolates.

Causes of losses including a Borna disease paralytic syndrome affecting young ostriches of one breeding organization over a five-year period (1989-1993).

Necropsy records and causes of mortality of ostriches up to 3 months old over a 5-year period (1989-1993) are presented. The data relate to one ostrich enterprise that comprises 10 breeding flocks, five rearing farms, and one hatchery. Causes of mortality are classified into nine major categories. The annual mortality percentages of all hatched ostriches over the 5-year period were 61%, 58%, 30%, 29%, and 16.6%, and the most significant cause of death was a paresis syndrome that accounted for 20%, 11%, 16%, 10.1%, and 2% mortality, respectively. Limb deformities and gastroenteritis were the other principal specific causes of mortality. The paresis syndrome was caused by an agent serologically related to Borna disease virus. Brain extracts from paralyzed ostriches, when given orally or intramuscularly to 5-week-old birds, reproduced the clinical signs and microscopic lesions. The mean time to death was less than 3 weeks for the intramuscularly infected group and was almost twice as long for the orally infected group.

Identification of a novel nephropathogenic infectious bronchitis virus in Israel.

A novel infectious bronchitis variant, designated as IS/885/00, associated with nephritis, was isolated from outbreaks in 23 broiler farms in Israel. The virus was first identified by reverse transcriptase-polymerase chain reaction and showed a distinct restriction fragment length polymorphism pattern from previously described Israeli isolates. Sequence analysis of the S1 gene and the deduced amino acid sequence revealed 97.2% protein similarity to genotype IS/ 720/99 and 71.6% similarity to the vaccine strain H120, the only strain permitted for use in this country. A database search in GenBank revealed a closely related isolate from Egypt, Egypt/Beni-Seug/01, with 96.6% similarity. Other published nephropathogenic infectious bronchitis virus strains/isolates shared less than 77% similarity with IS/885/00. A vaccine protection test in specific-pathogen-free chicks indicated 91% protection to the trachea and only 25% protection to the kidneys in vaccinated birds challenged with IS/885/00.

Applications of the polymerase chain reaction to detect infectious bursal disease virus in naturally infected chickens.

Reverse transcriptase-polymerase chain reaction was used for identification of Israeli isolates of infectious bursal disease virus (IBDV). The system was applied to tissue culture and to bursa of Fabricius from infected chickens; these latter samples had been frozen for as long as 4 years. From base homology analysis of published sequences of serotype 1 IBDV, two pairs of primers, targeted to amplify sequences from the VP2 and VP3 cistrons, were prepared. The two sets of primers could detect viruses of serotype 1. The primers directed to the cistrons could detect viral sequences from seven infected chickens. No reaction was detected with RNA extracted from bursal cells of healthy chickens or from uninfected cells. The sensitivity of the reaction was equivalent to 2.5 x 10(1) TCID50.

Approximation bounds for smooth functions in C(IRd) by neural and mixture networks.

We consider the approximation of smooth multivariate functions in C(IRd) by feedforward neural networks with a single hidden layer of nonlinear ridge functions. Under certain assumptions on the smoothness of the functions being approximated and on the activation functions in the neural network, we present upper bounds on the degree of approximation achieved over the domain IRd, thereby generalizing available results for compact domains. We extend the approximation results to the so-called mixture of expert architecture, which has received considerable attention in recent years, showing that the same type of approximation bound may be achieved.

On the optimality of neural-network approximation using incremental algorithms.

The problem of approximating functions by neural networks using incremental algorithms is studied. For functions belonging to a rather general class, characterized by certain smoothness properties with respect to the L2 norm, we compute upper bounds on the approximation error where error is measured by the Lq norm, 1< or =q< or =infinity. These results extend previous work, applicable in the case q=2, and provide an explicit algorithm to achieve the derived approximation error rate. In the range q< or =2 near-optimal rates of convergence are demonstrated. A gap remains, however, with respect to a recently established lower bound in the case q>2, although the rates achieved are provably better than those obtained by optimal linear approximation. Extensions of the results from the L2 norm to Lp are also discussed. A further interesting conclusion from our results is that no loss of generality is suffered using networks with positive hidden-to-output weights. Moreover, explicit bounds on the size of the hidden-to-output weights are established, which are sufficient to guarantee the established convergence rates.

Newcastle disease virus in little owls (Athene noctua) and African penguins (Spheniscus demersus) in an Israeli zoo.

Newcastle disease is a contagious and often fatal disease, capable of affecting all species of birds. A velogenic Newcastle disease virus (vNDV) outbreak occurred in an Israeli zoo, in which Little owls (Athene noctua) and African penguins (Spheniscus demersus) were found positive for presence of NDV. Some of them have died. The diagnostic process included: post-mortem examination, histopathology, real-time RT-PCR assay, virus isolation, serology, intracerebral pathogenicity index and phylogenetic analysis. A vNDV was diagnosed and found to be closely related to isolates from vNDV outbreaks that occurred in commercial poultry flocks during 2011. All isolates were classified as lineage 5d.

Development of a real-time TaqMan RT-PCR assay for the detection of H9N2 avian influenza viruses.

Avian influenza viruses (AIVs) of the H9N2 subtype are a major economic problem in the poultry industry in Israel. Most field isolates from the last decade differ significantly from H9N2 isolates from Europe and the USA, rendering published detection methods inadequate. This study aimed to develop a real-time TaqMan((R)) RT-PCR assay, based on a conserved region in the HA9 gene. The assay was validated with viruses representing different genetic subtypes and other common avian pathogens, and was found specific to H9N2. The real-time RT-PCR assay was compared to RT-PCR, which is in routine diagnostic use. Real-time RT-PCR was found to be more sensitive than RT-PCR by 1.5-2.5 orders of magnitude when testing tracheal swabs directly and by 2-3 orders of magnitude allantoic fluid after AIV propagation in embryonated eggs. Sensitivity was quantified by using 10-fold dilutions of the H9-gene amplification fragment, and real-time RT-PCR was found to be 10(4)-fold more sensitive than RT-PCR. Clinical samples, which included tracheal and cloacal swabs, as well as allantoic fluid, were tested by both methods. By real-time RT-PCR 20% more positive H9N2 samples were detected than by RT-PCR. The real-time RT-PCR assay was found suitable for detection and epidemiological survey not only of Israeli H9N2 viruses, but also for isolates from other parts of the world.