The attenuation surface for contrast sensitivity has the form of a witch’s hat within the central visual field

Over the full visual field, contrast sensitivity is fairly well described by a linear decline in log sensitivity as a function of eccentricity (expressed in grating cycles). However, many psychophysical studies of spatial visual function concentrate on the central ±4.5 deg (or so) of the visual field. As the details of the variation in sensitivity have not been well documented in this region we did so for small patches of target contrast at several spatial frequencies (0.7–4 c/deg), meridians (horizontal, vertical, and oblique), orientations (horizontal, vertical, and oblique), and eccentricities (0–18 cycles). To reduce the potential effects of stimulus uncertainty, circular markers surrounded the targets. Our analysis shows that the decline in binocular log sensitivity within the central visual field is bilinear: The initial decline is steep, whereas the later decline is shallow and much closer to the classical results. The bilinear decline was approximately symmetrical in the horizontal meridian and declined most steeply in the superior visual field. Further analyses showed our results to be scale-invariant and that this property could not be predicted from cone densities. We used the results from the cardinal meridians to radially interpolate an attenuation surface with the shape of a witch's hat that provided good predictions for the results from the oblique meridians. The witch's hat provides a convenient starting point from which to build models of contrast sensitivity, including those designed to investigate signal summation and neuronal convergence of the image contrast signal. Finally, we provide Matlab code for constructing the witch's hat.

Volunteering for success:mentoring as a form of student volunteering

Previous studies into student volunteering have shown how formally organized volunteering activities have social, economic and practical benefits for student volunteers and the recipients of their volunteerism (Egerton, 2002; Vernon & Foster, 2002); moreover student volunteering provides the means by which undergraduates are able to acquire and hone transferable skills sought by employers following graduation (Eldridge & Wilson, 2003; Norris et al, 2006). Within the UK Higher Education Sector, a popular mechanism for accessing volunteering is through formally organized student mentoring programmes whereby more ‘senior’ students volunteer to mentor less experienced undergraduates through a particular phase of their academic careers, including the transition from school or college to university. The value of student mentoring as a pedagogical tool within Higher Education is reflected in the literature (see for example, Bargh & Schul, 1980, Hartman,1990, Woodd, 1997). However, from a volunteering perspective, one of the key issues relates to the generally accepted conceptualisation of volunteering as a formally organized activity, that is un-coerced and for which there is no payment (Davis Smith, 1992, 1998; Sheard, 1995). Although the majority of student mentoring programs discussed in the paper are unpaid and voluntary in nature, in a small number of institutions some of the mentoring programs offered to students provide a minimum wage for mentors. From an ethical perspective, such payments may cause difficulties when considering potential mentors’ motivations and reasons for participating in the program. Additionally, institutions usually only have one or two paid mentoring programs running alongside several voluntary programmes – sometimes resulting in an over-subscription for places as paid mentors to the detriment of unpaid programs. Furthermore, from an institutional perspective, student mentoring presents a set of particular ethical problems reflecting issues around ‘matching’ mentors and mentees in terms of gender, race, ethnicity and religion. This is found to be the case in some ‘targeted’ mentoring programs whereby a particular demographic group of students are offered access to mentoring in an attempt to improve their chances of academic success. This paper provides a comparative analysis of the experiences and perceptions of mentors and mentees participating in a wide-range of different mentoring programs. It also analyzes the institutional challenges and benefits associated with managing large scale student volunteering programs. In doing so the paper adds to third sector literature by critiquing the distinctive issues surrounding student volunteering and by discussing, in-depth, the management of large groups of student volunteers. From a public policy perspective, the economic, educational, vocational and social outcomes of student volunteering make this an important subject meriting investigation. Little is known about the mentoring experiences of student volunteers with regards to the ‘added value’ of participating in campus-based volunteering activities. Furthermore, in light of the current economic downturn, by drawing attention to the contribution that student volunteering plays in equipping undergraduates with transferable ‘employability’ related skills and competencies (Andrews & Higson, 2008), this paper makes an important contribution to current educational and political debates. In addition to providing the opportunity for students to acquire key transferable skills, the findings suggest that mentoring encourages students to volunteer in other areas of university and community life. The paper concludes by arguing that student mentoring provides a valuable learning experience for student volunteer mentors and for the student and pupil mentees with whom they are placed.

Can the Q Link Ally,® a form of sympathetic resonance technology (SRT™), sttenuate scute mobile phone-related changes to neural function?

OBJECTIVES: Exposure to active mobile phones (MP) has been shown to affect human neural function as shown by the electroencephalogram (EEG). Although it has not been determined whether such effects are harmful, a number of devices have been developed that attempt to minimize these MP-related effects. One such device, the Q Link Ally® (QL; Clarus Products, International, L.L.C., San Rafael, CA), is argued to affect the human organism in such a way as to attenuate the effect of MPs. The present pilot study was designed to determine whether there is any indication that QL does alter MP-related effects on the human EEG. DESIGN: Twenty-four (24) subjects participated in a single-blind, fully counterbalanced crossover design in which subjects' resting EEG and phase-locked neural responses to auditory stimuli were assessed under conditions of either active MP or active MP plus QL. RESULTS: The addition of QL to the MP condition increased resting EEG in the gamma range and did so as a function of exposure duration, and it attenuated MP-related effects in the delta and alpha range (at trend-level). The addition of the QL also affected phase-locked neural responses, with a laterality reversal in the alpha range and an alteration to changes over time in the delta range, a reduction of the MP-related beta decrease over time at fronto-posterior sites, and a global reduction in the gamma range that increased as a function of exposure duration. No unambiguous relations were found between these changes and either performance or psychologic state. CONCLUSIONS: This pilot study suggests that the addition of the QL to active MP-exposure does affect neural function in humans, altering both resting EEG patterns and the evoked neural response to auditory stimuli, and that there is a tendency for some MP-related changes to the EEG to be attenuated by the QL.

Constructing a Canonical form of a Matrix in Several Problems about Combinatorial Designs

Partially supported by the Bulgarian Science Fund contract with TU Varna, No 487.

A Note on the L2-norm of the Second Fundamental Form of Algebraic Manifolds

2000 Mathematics Subject Classification: 53C42, 53C55.

Frugivory and Seed Dispersal by Crocodilians: An Overlooked Form of Saurochory?

Saurochory (seed dispersal by reptiles) among crocodilians has largely been ignored, probably because these reptiles are generally assumed to be obligate carnivores incapable of digesting vegetable proteins and polysaccharides. Herein we review the literature on crocodilian diet, foraging ecology, digestive physiology and movement patterns, and provide additional empirical data from recent dietary studies of Alligator mississippiensis. We found evidence of frugivory in 13 of 18 (72.2%) species for which dietary information was available, indicating this behavior is widespread among the Crocodylia. Thirty-four families and 46 genera of plants were consumed by crocodilians. Fruit types consumed by crocodilians varied widely; over half (52.1%) were fleshy fruits. Some fruits are consumed as gastroliths or ingested incidental to prey capture; however, there is little doubt that on occasion, fruit is deliberately consumed, often in large quantities. Sensory cues involved in crocodilian frugivory are poorly understood, although airborne and waterborne cues as well as surface disturbances seem important. Crocodilians likely accrue nutritional benefits from frugivory and there are no a priori reasons to assume otherwise. Ingested seeds are regurgitated, retained in the stomach for indefinite and often lengthy periods, or passed through the digestive tract and excreted in feces. Chemical and mechanical scarification of seeds probably occurs in the stomach, but what effects these processes have on seed viability remain unknown. Because crocodilians have large territories and undertake lengthy movements, seeds are likely transported well beyond the parent plant before being voided. Little is known about the ultimate fate of seeds ingested by crocodilians; however, deposition sites could prove suitable for seed germination. Although there is no evidence for a crocodilian-specific dispersal syndrome similar to that described for other reptiles, our review strongly suggests that crocodilians function as effective agents of seed dispersal. Crocodilian saurochory offers a fertile ground for future research.

A deimmunised form of the ribotoxin, α-sarcin, lacking CD4+ T cell epitopes and its use as an immunotoxin warhead

Fungal ribotoxins that block protein synthesis can be useful warheads in the context of a targeted immunotoxin. α-Sarcin is a small (17 kDa) fungal ribonuclease produced by Aspergillus giganteus that functions by catalytically cleaving a single phosphodiester bond in the sarcin–ricin loop of the large ribosomal subunit, thus making the ribosome unrecognisable to elongation factors and leading to inhibition of protein synthesis. Peptide mapping using an ex vivo human T cell assay determined that α-sarcin contained two T cell epitopes; one in the N-terminal 20 amino acids and the other in the C-terminal 20 amino acids. Various mutations were tested individually within each epitope and then in combination to isolate deimmunised α-sarcin variants that had the desired properties of silencing T cell epitopes and retention of the ability to inhibit protein synthesis (equivalent to wild-type, WT α-sarcin). A deimmunised variant (D9T/Q142T) demonstrated a complete lack of T cell activation in in vitro whole protein human T cell assays using peripheral blood mononuclear cells from donors with diverse HLA allotypes. Generation of an immunotoxin by fusion of the D9T/Q142T variant to a single-chain Fv targeting Her2 demonstrated potent cell killing equivalent to a fusion protein comprising the WT α-sarcin. These results represent the first fungal ribotoxin to be deimmunised with the potential to construct a new generation of deimmunised immunotoxin therapeutics.

Bovine serum albumin as the dominant form of dietary protein reduces subcutaneous fat mass, plasma leptin and plasma corticosterone in high fat-fed C57/BL6J mice

Acknowledgements The authors thank Harriett Schellekens from the University College Cork and Paula O’Connor from Teagasc Moorepark Food Research Centre for their assistance in procuring laboratory space and equipment. The present study was funded by Teagasc. B. L. M. was funded by the Walsh Fellowship Program. J. R. S. was supported by a 1000-talents professorship from the Chinese government. The funding bodies had no input on the design of the study or in the interpretation of the data.

HELLP Syndrome a Severe Form of Preeclampsia: a Comparative Study of Clinical and Laboratorial Parameters

The objective of this study was to compare clinical, laboratorial, maternal and perinatal results between HELLP Syndrome and severe Preeclampsia. An observational study comparing women with HELLP Syndrome (n=71) to women with severe preeclampsia (n=253) was done. The authors analyzed the early course of the pathologies and the outcomes in both groups. HELLP syndrome occurred in 28% of all the cases and was more frequent at gestational age before 32 weeks (n=39 – 55%) than severe preeclampsia (n=108 - 42%), with more newborns weighting less than 1500g (27 – 38.6% vs 65 – 25.6%; p=0.036). Thrombocytopenia below 100 000/μL (aOR, 2.14; 95% CI, 1.49 – 3.06) and LDH>1 000 UI/L (aOR: 5.17; 95% CI 2.19 – 12.16) were risk factors for HELLP. Maternal morbidity (eclampsia, abruptio placentae, and acute renal failure) was similar in both cohorts; eight stillbirths (6 in severe preeclampsia and 2 in HELLP Syndrome) occurred. There were no maternal deaths. In conclusion, in this study the authors confirmed that HELLP Syndrome is a severe form of preeclampsia with an earlier presentation in pregnancy, worst laboratorial findings and more prematurity rates.

Successful Treatment Using Simeprevir, Sofosbuvir and Rituximab of a Severe Form of Hepatitis C Virus-related Mixed Cryoglobulinemia with Cardiac Involvement

Numerous extrahepatic manifestations have been reported in hepatitis C virus (HCV) infection, particularly mixed cryoglobulinemia (MC). MC generally responds to clearance of HCV under pegylated-interferon plus ribavirin treatment. New direct-acting antiviral agents have been licensed for HCV under different combinations but have not been studied in severe forms of MC. Here, we present a case report describing a life-threatening form of MC with multivisceral involvement, which was successfully treated with concomitant rituximab, sofosbuvir and simeprevir. In light of the rapid clinical remission associated with sustained virological response and the excellent side-effect profile, this treatment should be considered as a first-line therapy in severe forms of MC.

A new form of land concentration in Colombia

This article aims to show how the Law 1448 of 2011, which explains reparation and restitution of victims, and the National Development Plan (NDP) 2011-2014 generate land concentration in Colombia -- This is due to how the NDP objectives disintegrate the Law 1448 objectives; this phenomenon could be explained using an agency model and the subsequent moral risk issue formed between the State and the victims -- Regarding these results, a game-theory model was built, and this effectively concludes that the Law 1448 and the NDP generate land concentration in Colombia

Investigation of un-American propaganda activities in the United States : Hearings before a Special Committee on Un-American Activities, House of Representatives, Seventy-fifth Congress, third session-Seventy-eighth Congress, second session, on H. Res. 282, to investigate (1) the extent, character, and objects of un-American propaganda activities in the United States, (2) the diffusion within the United States of subversive and un-American propaganda that is instigated from foreign countries or of a domestic origin and attacks the principle of the form of government as guaranteed by our Constitution, and (3) all other questions in relation thereto that would aid Congress in any necessary remedial legislation.

Martin Dies, chairman.

Criterion-related validity of the short form of the international physical activity questionnaire in adults who are Deaf

Background: To implement appropriate programs for promoting physical activity (PA) in people who are Deaf, it is important to have valid instruments for assessing PA in this population. Objective: The main purpose of this study was to examine the criterion validity of the short form of the International Physical Activity Questionnaire (IPAQ-S) in Deaf adults. Method: This study included 44 adults (18e65 years) of both genders (63.6% were females) who met the inclusion criteria. Objective measures of PAwere collected using accelerometers, which were worn by each participant during one week. After using the accelerometer, the IPAQ-S was applied to assess participants’ physical activity during the last 7 days. Results: There was no significant correlation between the average time spent in moderate to vigorous physical activity (MVPA) as measured by the accelerometer (40.1 6 24.5 min/day) and by the IPAQ-S (41.3 6 57.5 min/day). The IPAQ-S significantly underestimated the time spent in sedentary behavior (7.6 6 2.7 h/day vs. 10.1 6 1.6 h/day). Sedentary behavior and MVPA as measured by the accelerometer and the IPAQ-S showed limited agreement. Conclusions: Our results show some limitations on the use of IPAQ-S for quantifying PA among adults who are Deaf. The IPAQ-S tends to overestimate the MVPA and to underestimate sedentary behavior in adults who are Deaf.